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The linear power amplifier (LPA) suffers from low power supply utilization in the DC power supply mode, leading to reduced output efficiency. This paper constructs an efficient power supply mode based on closed‐loop dynamic power supply system (CLDPSs). The CLDPSs can generate a pair of bipolar dynamic power supplies based on a predetermined signal to provide power to LPA, which can maintain a small voltage drop between the power supply and the output of LPA, thereby improving the power supply utilization of LPA. In addition, the study also focuses on the conflicting relationship between the output ripple and the dynamic performance of the CLDPSs, for which a new parametric design of the LC filter circuit is proposed, aiming to achieve a balance between these two aspects. Finally, a voice coil motor driving platform is constructed for experimental testing. The results demonstrate that the output ripple and dynamic performance of the CLDPSs can be balanced. In comparison to the DC power supply mode, the CLDPSs power supply mode can enhance the efficiency of LPA by 2 times while the driving accuracy of voice coil motor is basically unchanged. [ABSTRACT FROM AUTHOR]

This paper proposes a Composition Piecewise Memory Polynomial (CPMP) digital predistortion model based on a Vector Switched (VS) behavioral model to address the challenges of severe nonlinearity and strong memory effects in wideband power amplifiers (PAs). To tackle this issue, two thresholds are calculated and used to segment the envelope values of the input signal according to the nonlinear distortion characteristics of the PA. In this approach, a Generalized Memory Polynomial (GMP) model is employed for the lower segment, a Memory Polynomial (MP) model is employed for the middle segment, and a higher-order GMP model is employed for the upper segment. By sharing the fundamental MP among the proposed segmented models and leveraging a design methodology that configures different cross terms, memory depths, and polynomial orders for each segment, this model achieves superior linearization performance while simultaneously reducing the computational complexity associated with model extraction. The experimental results demonstrate that the adjacent channel power ratio (ACPR) of the predistorted PA output signal using the proposed model improves from −36 dBc to −54 dBc, matching the performance of the GMP model. Furthermore, this performance is 0.5 dBc better than the Piecewise Dynamic Deviation Reduction (PDDR) and Decomposed Vector Rotation (DVR) models. Notably, the complexity of the proposed parameter extraction process is 28.8% of the DVR model, 21.79% of the GMP model, and 12.83% of the PDDR model. [ABSTRACT FROM AUTHOR]

Summary: An analysis of a single‐ended high‐efficiency broadband parallel‐circuit (PC) Class‐E power amplifier (PA) with a single reactance compensation technique (RCT) and low‐pass (LP) Chebyshev impedance transformer is first presented under low supply voltage. Analysis of the gate and drain voltage allows to determine the required optimum voltage values for the expected PA design objectives. Derivation and design procedure of the broadband matching network (MN) is provided, which can effectively filter out higher order harmonics and reduce circuit complexity. In addition, the load adaptability for this PA is studied, achieving higher than 67.87% drain efficiency (DE) in the case of load mismatch. A PC Class‐E PA based on NMOS transistor is designed and implemented to validate the analysis over a frequency band of 7–9.4 MHz. Experimental results show that the PA delivers 36.48–38.83 dBm output power with a DE of 84.91% to 86.91%, as well as achieves 83.98% to 86.28% power‐added efficiency (PAE), 19.48–21.83 dB gain with a low supply voltage of 12 V. It is also demonstrated that the experimental results exhibit good agreement with the simulation results, which prototype the radio frequency identification transmitter with broadband high‐efficiency and system compactness. To the author's knowledge, this study represents the first approach to design broadband PC Class‐E PA under low supply voltage for Internet of Things (IoT) applications at HF frequency band, such as electronic article surveillance (EAS) system. [ABSTRACT FROM AUTHOR]

In this paper, we present a high power-added efficiency (PAE) and high gain per stage 60 GHz power amplifier (PA). The proposed PA consists of a two-stage common-source amplifier that incorporates neutralization capacitors and compensation inductors to enhance both gain and efficiency. The gain characteristics are analyzed, demonstrating that the proposed design improves both gain and efficiency. Implemented in 65 nm CMOS technology, the PA achieves a saturated output power of 13.4 dBm at 60 GHz, with a maximum PAE of 26.7% from a 1 V supply. The output 1 dB compression point is 10.5 dBm, with a PAE of 16%. The PA occupies a core chip area of 0.094 mm2. [ABSTRACT FROM AUTHOR]

This paper presents a Doherty power amplifier (DPA) integrated circuit (IC) designed to have enhanced gain, efficiency, and AM-AM characteristics through a dynamic power dividing technique, which can control the power dividing ratio according to the input power. Since this multi-purpose dynamic power dividing network also provides the phase offset and impedance matching at the interstage network needed for appropriate DPA operation, the active IC area could be reduced. To verify the proposed technique and its analysis, the DPA was implemented with a 28 nm bulk CMOS process for the fifth-generation (5G) new radio (NR) millimeter-wave frequency band of 23.5–27.5 GHz. The measured results showed a gain of 20.3–21.9 dB, saturated output power of 14.0–15.2 dBm, power added efficiency (PAE) of 22.8–26.7% at the peak power, and PAE of 14.6–17.6% at the 6 dB output power back-off (OBO). [ABSTRACT FROM AUTHOR]

RF power amplifier (RF PA) finds its application in almost all the areas of electronics, mobile communication being identified as a major area. The paper performs a comparative efficiency analysis of RF power amplifiers operating with a fixed bias and an envelope tracking bias. Simulations are performed using Keysight advanced design system (ADS) tool. A class a RF PA operating at a 12 dB gain is fixed for the work. 16 QAM LTE signal operating at 5 MHz input frequency, with a peak to average power ratio (PAPR) of 6.0 dB is used as input signal. An envelope simulation at 2.5 GHz is performed on the RF power amplifier. Simulation result shows an improvement of 12% in power added efficiency (PAE) at 6 dB back-off and 6.422% in mean PAE while using envelope tracking power amplifiers, compared to RF PA with fixed supply. Envelope tracking power amplifiers reduced AM/AM distortions also by a factor of 0.248. The results obtained are much better than that obtained using a conventional RF PA with fixed bias. RF PA being the most power dissipative block in a mobile handset, improving its efficiency contributes directly to a great improvement in the battery lifetime of mobile phones. The major challenges faced by envelope tracking PA (ETPA) designers in achieving this efficiency improvement is also delineated in the paper. [ABSTRACT FROM AUTHOR]

The employment of Intelligent Reflecting Surface (IRS) in MIMO systems has been extensively studied as a feasible alternative to relays. IRS can operate either actively or passively. In the case of a passive IRS configuration, no signal processor or amplifier is required, allowing for signal reflection in the desired phase shift with lower power consumption and cost. However, the passive IRS gain is significantly decreased due to the path loss in the IRS channel. In the active IRS structure, each reflective element is fitted with a power amplifier that enables it to reflect the signal to the intended destination at an appropriate power level. This confers a greater benefit to the system than a passive structure. Consequently, a hybrid active–passive IRS is recommended as it results in a higher sum rate, more energy gain, and a balance between the higher rate and lower energy consumption. In this paper, we examine a practical Rician channel hybrid IRS-assisted multiuser MIMO system with the goal of maximizing the sum rate. To accomplish this, we simplified the objective function of the main problem using the Fractional Programming (FP) method and modified the formulations in order to divide the main problem into a series of sub-problems. Then, using the Block Coordinate Descent (BCD) method and placing sub-problems into consecutive blocks, we solve each sub-problem to obtain the optimal solution for each block and, ultimately, the answer to the main problem. Finally, simulations were conducted for the proposed scenario, indicating that the sum rate of the hybrid IRS structure varied between the active and inactive IRS structure, depending on transmission power. However, adjusting the number of elements in the active and passive structures can achieve higher overall rates than traditional structures at low power levels. [ABSTRACT FROM AUTHOR]

ABSTRACT In this paper, a broadband high‐efficiency power amplifier (PA) with filtering characteristics is proposed. This PA is designed using a series of inverse continuous modes (SICMs) and adds a novel coupled microstrip line filter structure. The terminal of this structure is composed of microstrip lines cascaded to improve the out‐of‐band suppression effect. This filter can achieve low in‐band insertion loss, high passband selectivity, as well as deep stopband rejection performance simultaneously. A PA was designed and implemented using a 10 W GaN HEMT device, verifying its wideband characteristics. The measurement result shows that the 39.6–41.6 dBm output power (Pout), 61.6%–73.7% drain efficiency (DE), and 8.6–10.8 dB gain are achieved at 2.2–2.9 GHz. [ABSTRACT FROM AUTHOR]

One of the most advanced waveforms available in the beyond-fifth-generation radio (B5GR) framework is nonorthogonal multiple access (NOMA). The power amplifier (PA) of the NOMA structure performs less efficiently when the signal is strong and the peak-to-average power ratio (PAPR) is high. This study applies a hybrid algorithm to the NOMA structure, combining fractal partial transmit sequence (PTS), A-law companding, and the bacterial foraging algorithm (BFA). Fractals are known for their self-repeating structures at different scales, allowing for efficient coverage and exploration of space. Fractals enhance the bacteria foraging algorithm (BFA) by improving search efficiency, enabling better exploration of complex, multi-dimensional optimization landscapes. Similarly, BFA balances exploring the search in promising areas. We utilized BFA to achieve optimal phase factors for the PTS algorithm and applied A-Law companding to the NOMA symbols to further enhance the structure’s performance. The intermediate computational complexity in the Rician and Rayleigh channels improves PAPR, bit error rate (BER), and power spectral density performance. Simulation results reveal that the performance of the proposed hybrid method is superior to that of existing PAPR reduction algorithms and substantially enhances the efficiency of NOMA. [ABSTRACT FROM AUTHOR]

Optical orthogonal time frequency space (OTFS) is better at handling Doppler shifts and multipath fading, making signals more reliable and valuable in places with much movement beyond the fifth generation (B5G). Using practical power amplifiers at the transmitter causes power inefficiency and signal distortion because of the OTFS system’s high peak-to-average power ratio (PAPR), severely reducing system efficiency. Combining partial transmit sequence (PTS) and selective mapping (SLM), a technique known as PTS+SLM, reduces peak power. While SLM generates numerous phase-modulated signal candidates and chooses the one with the lowest PAPR, PTS separates the signal into sub-blocks and optimizes their phases to decrease peak power. With few changes to the signal structure, this dual strategy effectively reduces PAPR while improving power spectral density (PSD) efficiency. As a result, we ensure the accuracy and dependability of the transferred data by maintaining the bit error rate (BER). Fractal optimization methods could be applied to these algorithms. For example, fractal-inspired optimization techniques might be used to explore the phase space more effectively or to discover new phase sequences that result in lower PAPR. According to the simulation findings, the suggested PTS+SLM method works better than the traditional PTS and SLM methods. [ABSTRACT FROM AUTHOR]

Orthogonal time frequency selectivity is considered one of the most promising advanced waveforms for high-mobility conditions in beyond-fifth-generation networks. A high peak-to-average power ratio in orthogonal time frequency introduces nonlinearity and degrades the power amplifier performance. In this work, we propose a novel automatic amplitude reduction neural network algorithm combined with partial transmission sequence and selective mapping methods using the Vendermonde matrix for generating phase sequences. In a conventional selective mapping methods or partial transmission sequence, selecting an optimal phase increases the complexity, which is overcome via Vendermonde matrix in a proposed framework. The minimization of the peak-to-average power ratio is obtained at the double-stage process: in the first stage, the threshold amplitude is set, and the amplitude exceeding the threshold is reduced by using an automatic amplitude reduction neural network and then the partial transmission scheme or selective mapping methods. The simulation results reveal that, compared with the conventional algorithms, the proposed algorithms yield a significant peak average-to-power ratio, bit error rate, and power spectrum density performance. [ABSTRACT FROM AUTHOR]

A novel spoof surface plasmon polaritons (SSPP) structure is applied to the design of radio frequency (RF) power amplifiers (PAs) in this work. Both standard SSPP and the proposed SSPP structures are used as input and output matching networks of a multioctave PA design. An analysis and discussion of the electromagnetic characteristics of the proposed SSPP structures is presented. Further optimization of PA performance is achieved by utilizing the gradient algorithm of the Advanced Design System tool. According to the test results, the newly developed SSPP‐based PA achieves output power ranging from 40.5 to 42.6 dBm, while the power additional efficiency varies between 60% and 66.55%, with a total layout size of 59.8 mm × 14.6 mm in the frequency band of 0.8–3.2 GHz. In comparison with recent published work, the PA designed in this work expands the bandwidth while maintaining high output power and efficiency while being smaller in size. [ABSTRACT FROM AUTHOR]

With the demand for the miniaturization and integration of wireless power transfer (WPT) systems, higher frequency is gradually becoming the trend; thus, the power electronic device has become one of the main reasons for limiting the development. Therefore, further research on high-frequency inverters and purposeful design according to the characteristics of WPT systems are of great significance to promote the development of high-frequency WPT technology. There is still no literature that summarizes all the inverter circuits that can be applied to WPT systems, which makes it extremely difficult to find an inverter that meets the designer's requirements. This paper reviews the high-frequency inverters for WPT systems, summarizes the derived topologies based on power amplifiers and H-bridge inverters, investigates the main factors restricting the development of high-frequency inverters, and analyzes the research directions for future development. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive study on the design and performance of a high-power amplifier (PA) covering a broad frequency band from 0.1 to 4.8 GHz. Leveraging a 10 W GaN device, the amplifier achieves output power levels surpassing 10 W across the entire frequency band. Furthermore, the power-added efficiency (PAE) of the amplifier ranges from 47% to 59%, indicating its energy-efficient operation. With consistent gain characteristics varying between 7 and 15 dB, the design ensures reliable signal amplification for diverse applications. Notably, the approach introduces a simplified output matching network based on an LC network, prioritizing practicality without sacrificing performance. Additionally, comprehensive guidance is provided on utilizing the Smith chart for streamlined amplifier design, enabling engineers with an accessible methodology. Through a meticulous analysis, this work contributes to advancing the field of high-power amplification, offering enhanced performance and usability for next-generation wireless communication systems. [ABSTRACT FROM AUTHOR]

In the rapidly advancing field of 5G technology, efficient thermal management is essential for enhancing the performance and reliability of high-power-density integrated circuits (ICs). This paper introduces an innovative approach to cooling these critical components, significantly surpassing traditional methods. Our design optimizes heatsink and fan configurations through systematic experimentation, varying fin shapes, heatsink dimensions, and fan speeds. The results demonstrate that fan velocity is the most critical factor in reducing IC temperatures, as increased airflow dramatically lowers thermal output. Expanding the heatsink surface area further improves heat dissipation by enhancing airflow interaction, while a larger copper heatsink boosts thermal conduction, effectively reducing the final IC temperature. These optimizations streamline the cooling process, minimizing the need for more complex and expensive equipment. This research sets a new benchmark in thermal management, fostering the development of more efficient and reliable electronic systems in the era of advanced wireless communications. Our approach brings a new dimension to existing research by focusing on the optimization of heatsink and airflow designs specifically for ICs. While previous studies have explored broader thermal management strategies, our work addresses specific challenges in heat dissipation by refining geometric configurations and fan speed adjustments. These optimizations result in measurable improvements in both efficiency and scalability, particularly within the context of high-power 5G systems. [ABSTRACT FROM AUTHOR]

ABSTRACT A novel Wiener‐type dynamic neural network (Wiener‐type DNN) method for large signal modeling of power amplifiers (PAs) is proposed in this paper. In this method, the proposed model structure for the PA contains two Wiener‐type DNNs to describe the input impedance and the amplification efficiency, respectively. The Wiener‐type DNN includes a simplified linear dynamic equation module and a nonlinear static equation module. For the simplification process of the linear dynamic equation, it is proposed to process fundamental frequency components of the large signal harmonic data of the PA by vector fitting. The neural network is used to implement the static equation in the Wiener‐type DNN. The formulas for training the proposed Wiener‐type DNN model of the PA using large signal data are derived. The training algorithm of the PA model is proposed to improve the training efficiency. A Motorola MOSFET PA example and a Freescale lateral double‐diffused MOSFET PA example are present to validate the proposed Wiener‐type DNN method. For the Motorola MOSFET PA, a dynamic neural network (DNN) model and a time‐delay deep neural network (TDDNN) are established for comparison. For the Freescale PA, the DNN model is used for comparison experiment. The comparison figures show that the Wiener‐type DNN model has better convergence properties than the DNN model in the nonlinear region of the PA. The established accurate PA model is conducive to the design of subsequent communication circuits. [ABSTRACT FROM AUTHOR]

Modern communication networks require improved signal quality and spectrum efficiency. Modern wireless communication relies heavily on the multiple input multiple output (MIMO) technology to improve spectrum efficiency and achieve faster data rates. However, the performance of MIMO systems is significantly hampered by non-linear distortions in power amplifiers (PA), especially under dynamic operating conditions. Traditional methods to reduce these distortions often lack the adaptability required for effective optimization. The proposed dynamic nonlinear distortion adaptive optimization analysis (DNDAOA) therefore introduces an adaptive approach that dynamically adjusts the pre-distortion signals using real-time feedback mechanisms. DNDAOA effectively reduces non-linear distortions and thus improves the performance of MIMO systems. Simulation results show that DNDAOA significantly increases spectrum efficiency, reduces error rates, and improves signal quality. This method is widely used in areas such as wireless telecommunications, internet of things (IoT), autonomous vehicles, and smart infrastructure, driving advances in connectivity, reliability, and data integrity. [ABSTRACT FROM AUTHOR]

Summary: In this paper, an out‐of‐band suppression enhanced high‐efficiency millimeter‐wave (mm‐wave) gallium nitride (GaN) microwave monolithic integrated circuit (MMIC) filtering power amplifier (FPA) is presented. A modified elliptic response bandpass filtering (BPF) output matching network (OMN) is used to achieve low loss and high out‐of‐band rejection. The circuit of the presented BPF OMN is given and its synthesized method is introduced. The simulated S‐parameters show that the OMN has a low‐loss in‐band response and a desired out‐of‐band rejection performance with two transmission zeros (TZs). To demonstrate this idea, a two‐stage 24–28‐GHz GaN MMIC PA is designed and implemented in a 0.15‐μm GaN‐on‐SiC process, with a mask area of 2.4 × 1.0 mm2. Experimental results show that the realized MMIC PA achieves a small signal gain of 18.8 dB from 24 to 28 GHz with ±1.2‐dB gain flatness and 40‐dB rejection at 19.43 and 33.8 GHz. The saturated power‐added efficiency (PAE) is higher than 29% from 24 to 28 GHz, with a peak PAE of 36.3% at 27 GHz. The output power is within the range of 33.8 to 35.6 dBm in the operating band. For a 100‐MHz five‐carrier LTE signal, the PA can achieve ACLR better than −40 dBc over the band with digital predistortion. [ABSTRACT FROM AUTHOR]

Summary: This paper proposes a mixed design strategy to expand the power back‐off (OBO) range of the pseudo‐Doherty load‐modulation balanced power amplifier (LMBA). An asymmetric LMBA configuration is employed to increase the OBO range. The two PA branches of the balanced PA operate in different class‐C modes, thereby obtaining two OBO points. Further, an asymmetrical coupler is also introduced into the asymmetrical LMBA architecture to expand the OBO. Here, the relationship between the OBO and coupler's parameters and asymmetrical configuration parameters is built. The behaviors of the proposed PA as a function of input power are derived when several representative parameters are chosen. To validate the proposed topology, a PA with an OBO of 15 dB operating across 3.4–3.6 GHz is designed, fabricated, and tested. Measurements illustrate that the PA can deliver a saturated output power of 43.6–44.5 dBm with a drain efficiency ranging from 70% to 72%. Drain efficiencies are between 50% and 68% at the OBO of 15 dB. The LMBA implemented here shows state‐of‐the‐art performance in terms of the OBO range. [ABSTRACT FROM AUTHOR]

A fully integrated gallium arsenide (GaAs) heterojunction bipolar transistor (HBT) power amplifier (PA) for wireless local area network 802.11ax applications is presented in this paper. The structure consists of two‐stage power cells. To satisfy the high linearity requirements of IEEE 802.11ax, we analyzed the distortion of amplitude‐to‐amplitude and amplitude‐to‐phase. Due to the thermal and voltage sensitivity of GaAs HBT, an adaptive bias circuit is designed to ensure linearity. Moreover, an efficient passive output matching network is designed by analyzing the efficiency of the passive network. The design electromagnetic structure is fabricated in a 2‐μm GaAs HBT process. Under continuous wave testing, the output power reaches 27.2 dBm and the maximum efficiency of 28% at 2.4 GHz. Under the excitation of a 40 MHz 1024‐quadratic amplitude modulation signal, the output power meeting error vector magnitude of −35 dB reaches 16.8–17.2 dBm from 2.4 to 2.5 GHz. [ABSTRACT FROM AUTHOR]

This paper presents a thorough robust Class-AB power amplifier design and its application in pressure-mode sensor-on-chip nonlinearity correction. Considering its use in piezoresistive sensing applications, a gain-boosting-aided folded cascode structure is utilized to increase the amplifier's gain by a large amount as well as enhancing the power rejection ability, and a push–pull structure with miller compensation, a floating gate technique, and an adaptive output driving limiting structures are adopted to achieve high-efficiency current driving capability, high stability, and electronic environmental compatibility. This amplifier is applied in a real sensor nonlinearity correction on-chip system. With the help of a self-designed 7-bit + sign DAC and a self-designed two-stage operational amplifier, this system is compatible with nonlinear correction at different signal conditioning output values. It can also drive resistive sensors as small as 300 ohms and as high as tens of thousands of ohms. The designed two-stage operational amplifier utilizes the TSMC 0.18 um process, resulting in a final circuit power consumption of 0.183 mW. The amplifier exhibits a gain greater than 140 dB, a phase margin of 68°, and a unit gain bandwidth exceeding 199.76 kHz. The output voltage range spans from 0 to 4.6 V. The final simulation results indicate that the nonlinear correction system designed in this paper can correct piezoresistive sensors with a nonlinearity of up to ±2.5% under various PVT (Process–Voltage–Temperature) conditions. After calibration by this system, the maximum error in the output voltage is 4 mV, effectively reducing the nonlinearity to 4% of its original value in the worst-case scenario. [ABSTRACT FROM AUTHOR]

One of the most common methods to protect electronic and telecommunication systems in a high‐power electromagnetic (HPEM) environment is using a conductive enclosure. Amplifiers are the vital parts in transmitter and receiver systems as the main components of a telecommunication system, so investigating the effects of HPEM waveform on their performance is very important. The Presence of apertures in the body of the conductive enclosure, as well as non‐linear elements such as transistors in amplifiers, adds to the complexity of examining the coupling of electromagnetic fields on the performance of amplifiers. Considering the importance of the topic, in this study, the impact of the HPEM waveform on the power amplifier inside the conductive enclosure has been investigated. By using the finite difference delay modelling (FDDM) numerical method as a stable method followed by the vector fitting (VF) method, the electromagnetic problem has become a circuit problem, which allows examining the response of the power amplifier and any circuit, including non‐linear elements against the interference field. Responses of bipolar linear and non‐linear components in the perforated conductive enclosure by the proposed method have been compared with the results obtained by computer simulation technology microwave studio (CST‐MWS) for verification. [ABSTRACT FROM AUTHOR]

ABSTRACT In this paper, the iCGF−1 mode is proposed to compensate the amplitude‐to‐amplitude modulation (AM/AM) distortion of the traditional continuous class F−1 mode while maintaining the high efficiency. The AM/AM profile of the iCGF−1 mode is mathematically expressed simultaneously as a function of the input nonlinearity parameter γ$$ \gamma $$ and conduction angle α$$ \alpha $$, which makes the iCGF−1 mode more flexible in controlling the AM/AM profile. The first inflection point of the AM/AM profile can be moved to a higher output power level through theoretical deduction by adjusting the second harmonic source impedance Z2S$$ {Z}_{2S} $$ and gate bias voltage to increase the values of γ$$ \gamma $$ and α$$ \alpha $$. This flattens the AM/AM profile while the efficiency profile remains almost the same as that of the traditional continuous class F−1 mode. The performance of the iCGF−1 mode is verified through simulation and experimental measurements. The iCGF−1 PA is fabricated with CGH40010F and has a frequency range of 2–2.6 GHz. The drain efficiency is 70.1%–77.9%, and the output power is 41.1–41.7 dBm. The linearity is tested with a 100 MHz 5G NR signal (the peak average power ratio (PAPR) is 8.5 dB) at 2.3 GHz. The worst adjacent channel power ratio (ACPR) is −32.3 dBc without digital predistortion (DPD) and −52.1 dBc with DPD. The results show that the iCGF−1 mode has successfully compensated the AM/AM distortion of the traditional continuous class F−1$$ {}^{-1} $$ mode and maintaining high efficiency. [ABSTRACT FROM AUTHOR]

This article covers the potential of Filter Bank Multicarrier (FBMC) modulation as an alternative to be used in the future 5 G wireless networks in which Massive Multiple-Input Multiple-Output (MIMO) is implemented. The 'energy efficient Massive Multiple Input Multiple Output (M-MIMO) Filter bank Multi-carrier Modulation (FBMC)' is necessary and beneficial for the upcoming wireless communiqué system. This is because there is an ever-increasing demand for higher data rates with higher Spectral Efficiency (SE). This paper compares orthogonal frequency division multiplexing (OFDM) with FBMC. This helps to evaluate the Spectral Efficiency (SE) of a Massive MIMO system that performs transmission under a unicellular environment. The variation in Massive MIMO allows equilibrium of the channel because FBMC has extra benefits due to the confinement of the subcarrier in an assigned range. However, the high Peak to Average Power Ratio (PAPR) in an M-MIMO-FBMC system is recognised as a serious problem that causes nonlinear signal deformation and restricts the effectiveness of the Power Amplifier (PA). In this work, to increase the SE in the system, the antenna count is optimised, such that the SNR or SNDR is maximum. For this, the antenna counts are optimised via Self Improved SSO with a Chaotic Map (SISSO-CM). [ABSTRACT FROM AUTHOR]

This paper introduces a novel differential combiner designed to effectively address parasitic capacitances of transistors used in power amplifier (PA) designs with precise compensation at a specified frequency. The combiner consists of a λ / 4 transmission line with an integrated capacitor of value 2 C O U T at its midpoint, which ensures accurate cancellation of parasitic effects. This design connects the drain pins of two transistors, which are considered identical in this configuration. By eliminating the need for complex parasitic compensation techniques, this method significantly simplifies the design process of Doherty Power Amplifiers (DPAs). Extensive simulations validate the effectiveness of this approach, highlighting its potential as a versatile and straightforward solution for next-generation communication systems. [ABSTRACT FROM AUTHOR]

This paper outlines a design approach for biomedical wireless power transfer systems with a focus on three-coil inductive links for neonatal intensive care unit applications. The relevant literature has been explored to support the design approach, equations, simulation results, and the process of experimental analysis. The paper begins with a brief overview of various power amplifier classes, followed by an in-depth examination of the most common power amplifiers used in biomedical wireless power transfer systems. Among the traditional linear and switching amplifier classes, class-D and class-E switching amplifiers are highlighted for their enhanced efficiency and straightforward implementation in biomedical contexts. The impact of load variation on these systems is also discussed. This paper then explores the basic concepts and essential equations governing inductive links, comparing two-coil and multi-coil configurations. In the following, the paper discusses foundational coil parameters and provides theoretical and experimental analysis of both two-coil and multi-coil inductive links through step-by-step measurement techniques using lab equipment and addressing the relevant challenges. Finally, a case study for neonatal intensive care unit applications is presented, showcasing a wireless power transfer system operating at 13.56 MHz for powering a wearable device on a patient lying on a mattress. An inductive link with a transmitter coil embedded in a mattress is designed to supply power to a load at distances ranging from 4 cm to 12 cm, simulating the mattress-to-chest distance of an infant. the experimental results of a three-coil inductive link equipped with a Class-E power amplifier are reported, demonstrating power transfer efficiency ranging from 75% to 25% and power delivery to a 500 Ω -load varying from 340 mW to 25 mW over various distances. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to present a detailed design procedure for a highly efficient sequential load-modulated balanced amplifier (SLMBA) to provide an in-depth analysis of this complex power amplifier (PA) architecture. SLMBA's basic theory is presented and discussed. An SLMBA with a frequency range from 2.45 GHz to 2.65 GHz was implemented and then measured in order to validate the proposed design methodology. In both saturation and back-off states, the fabricated SLMBA exhibits extremely high efficiency and output power. It delivers a maximum output power of 43~44.4 dBm and a drain efficiency (DE) of 71.6~75% at saturation, a DE of 63.5~66% at 6 dB output back-off (OBO) state, a DE of 61.8~66% at 10 dB OBO state, and a DE of more than 51% at 12 dB OBO state in the targeted frequency band. The achieved results demonstrate the effectiveness of the proposed design procedure. [ABSTRACT FROM AUTHOR]

This paper presents the theory, design, and application of a dual-branch series-diode analog pre-distortion (APD) linearizer to improve the linearity and efficiency of a K-band high-power amplifier (HPA). A first-of-its-kind, frequency-dependent large-signal APD model is presented. This model is used to evaluate different phase relationships between the linear and nonlinear branches, suggesting independent gain and phase expansion characteristics with this topology. This model is used to assess the impact of diode resistance, capacitance, and ideality factors on the APD characteristics. This feature is showcased with two similar GaAs diodes to find the best fit for the considered HPA. The selected diode is characterized and modeled between 1 and 26.5 GHz. A comprehensive APD design and simulation workflow is reported. Before fabrication, the simulated APD is evaluated with the measured HPA to verify linearity improvements. The APD prototype achieves a large-signal bandwidth of 6 GHz with 3 dB gain expansion and 8° phase rotation. This linearizer is demonstrated with a 17–21 GHz GaN HPA with 41 dBm output power and 35% efficiency. Using a wideband 750 MHz signal, this APD improves the noise–power ratio (NPR) by 6.5–8.2 dB over the whole HPA bandwidth. Next, the HPA output power is swept to compare APD vs. power backoff for the same NPR. APD improves the HPA output power by 1–2 W and efficiency by approximately 5–9% at 19 GHz. This efficiency improvement decreases by only 1–2% when including the APD post-amplifier consumption, thus suggesting overall efficiency and output power improvements with APD at K-band frequencies. [ABSTRACT FROM AUTHOR]

In this study, we explored the potential for average power scaling in a monolithic side-counter-pumped combiner based on Yb-doped tapered fibers. The optimal configuration of the pump-feeding fibers was determined through experiments with passive signal fibers. It is shown that pump coupling efficiencies higher than 83% can be achieved for fibers coated with low-index polymer with a numerical aperture (NA) around 0.45 and more than 74% for fibers with second cladding made of F-doped silica (NA ~ 0.26) for pump power up to 100 W. It was shown that the main factor significantly reducing the pump-to-signal conversion efficiency in the developed monolithic Yb-doped tapered fiber amplifiers is the pump leakage due to the decrease of the first cladding diameter along the tapered fiber and the corresponding increase of the pump NA (which becomes higher than the NA of the first cladding). A solution to this problem based on a narrowing diameter at the output end of the tapered fiber was proposed and realized. The record-high average power of 41 W, with a coupling efficiency of 77.7%, was demonstrated in a monolithic amplifier with a threshold of nonlinear effects of more than 600 kW (for ps pulses). Prospects for further power scaling in all-fiber sub-MW peak power amplifiers are discussed. [ABSTRACT FROM AUTHOR]

The active component nonlinear (NL) effect causes undesirable RF and microwave system electromagnetic interference (EMI) problems which penalizes the communication system performance by signal distortion. Therefore, a relevant NL component measurement method is needed to predict the transceiver system EMI effect. However, the NL measurement characterization of RF and microwave active devices remains a fastidious and time cost task. An innovative NL test bench automatized by LabVIEW®control interface is featured in this research work. The design technique of the NL test methodology is described. The developed automatic test bench is tested with a microwave power amplifier (PA) operating at 2.4 GHz based on double-frequency (DF) method. The experimental test setup including the LabVIEW®test control parametrization and data acquisition is described. The test bench effectiveness was assessed by the third-order intermodulation (IMD3) PA measurement with DF method. The theoretically calculated and measured IMD3 amplitudes based on DF input signal are in very good correlation. Thanks to its advantages in terms of simplicity, flexibility, and time cost, the innovative NL automatic test bench is very useful for transceiver system EMI analyses. [ABSTRACT FROM AUTHOR]

Featured Application: For industrial-scale extinguishment, natural processes such as acoustic wave propagation can be used. As proven, a technology described in the article using modulated and unmodulated waves can be applied to extinguish flames, as well as to control them. The results presented in the article are limited to extinguishing candle flames, but in the long term, this technique can be used to extinguish flames (especially firebreaks) from various materials (Classes C and B). This inexpensive, versatile, and environmentally safe method can provide a supporting or additional means of fire protection, especially useful in the first stage of fire occurrence. This technique appears to be environmentally friendly (it does not leave stains and does not emit chemicals). Moreover, acoustic waves can be applied to reduce the intensity of smoke and harmful substances in the ambient air, the presence of which is the result of fires (future plans). Due to the consequences of fires, new and environmentally friendly firefighting techniques are constantly being sought. There are many methods of extinguishing flames around the world. One of them is a technique that uses acoustic waves for extinguishing, which can be seen as repeated sequences of molecular compression and dilation (acoustic waves transfer energy due to the movements of molecules and atoms). This research shows a new approach to the extinguishing of flames. In practice, the extinguishing capabilities of low-frequency modulated and unmodulated acoustic waves were tested on a laboratory station, the main component of which was a high-powered acoustic extinguisher (the nominal power was equal to 1700 W). A B&C 21DS115 woofer was applied as a sound source. A Rigol DG4102 and a Proel HPX2800 were used as an acoustic generator with a modulator and as a power amplifier, respectively. In this paper, the presented results are limited to extinguishing candle flames. The tests made it clear that flames can be extinguished using properly generated and directed acoustic waves. As the results indicate, it becomes possible to effectively extinguish flames with both low-frequency modulated and unmodulated acoustic waves, which brings many benefits. [ABSTRACT FROM AUTHOR]

ABSTRACT The general electromagnetic (EM) theory has not yet been applied to the analysis of Class F (CF) power amplifier (PA). In this paper, an alternative approach for CF PA is presented based on the EM theory. Theoretical analysis shows that the CF PA can be divided into two broad categories, forward voltage gain, and reflected voltage gain PA. The existing CF PA belongs to the reflected voltage gain PA. Even though both the CF PAs have the same voltage gain, the PA with forward voltage gain provides higher fundamental power Ps,1@F and drain efficiency PAE@F than that CF PA with reflected voltage gain and Class B PA. This important conclusion is obtained as a result of this analysis, which cannot be explained by available theory in the literature. The theoretical analysis is validated at 2.2 GHz by fabrication and measurements. According to the results, Ps,1@B = 31.8 dBm and PAE@B = 53.27% in Class B PA. In CF PA with reflected voltage gain, Ps,1@F = 30.20 dBm and PAE@F = 48.6%. Both cases have lower power and PAE as compared to new category of CF PA. This new CF PA with forward voltage gain has, Ps,1@F = 33.04 dBm and PAE@F = 63.7%. [ABSTRACT FROM AUTHOR]

Active switching components are employed to propose a novel compact dual-band matching network (MN) with an adapted frequency in this paper. The design method involves the integration of active switching devices, stepped impedance resonator (SIR), and microstrip transmission line into the frequency response of a dual-band MNs. The PIN diode is employed as an active switching device in the proposed structure to increase the bandwidth of the MNs and attain the desired frequency. The dual-band MNs that are being proposed are fabricated and designed on the Rogers RO4350B substrate for use in Wireless Local Area Networks (WLANs). The simulation results demonstrate a high degree of congruence with the measurements. The maximal insertion losses and return losses in the first band are -1.3 and -24 dB, respectively. In the second band, they are -2.2 and -20.69 dB. The primary benefits of the proposed dual-band MNs are their high attenuation between two passbands, frequency matching capability, suitable return loss, and low insertion loss. [ABSTRACT FROM AUTHOR]

Protecting sensitive patient data, such as electrocardiogram (ECG) signals, during RF wireless transmission is essential due to the increasing demand for secure telemedicine communications. This paper presents an innovative chaotic-based encryption system designed to enhance the security and integrity of telemedicine data transmission. The proposed system utilizes a multi-scroll chaotic system for ECG signal encryption based on master–slave synchronization. The ECG signal is encrypted by a master system and securely transmitted to a remote location, where it is decrypted by a slave system using an extended state observer. Synchronization between the master and slave is achieved through the Lyapunov criteria, which ensures system stability. The system also supports Orthogonal Frequency Division Multiplexing (OFDM) and adaptive n-quadrature amplitude modulation (n-QAM) schemes to optimize signal discretization. Experimental validations with a custom transceiver scheme confirmed the system's effectiveness in preventing channel overlap during 2.5 GHz transmissions. Additionally, a commercial RF Power Amplifier (RF-PA) for LTE applications and a development board were integrated to monitor transmission quality. The proposed encryption system ensures robust and efficient RF transmission of ECG data, addressing critical challenges in the wireless communication of sensitive medical information. This approach demonstrates the potential for broader applications in modern telemedicine environments, providing a reliable and efficient solution for the secure transmission of healthcare data. [ABSTRACT FROM AUTHOR]

A 47–52‐GHz power amplifier (PA) Microwave Monolithic Integrated Circuit (MMIC) with silicon carbon (SiC)‐based gallium nitride (GaN) was reported in this work. The circuit solution gives particular consideration to the loss of matching the output matching network. In pulse conditions, the PA can reach a maximum saturated output power of 43 dBm (20 W) with typical gain values of 18 dB and power‐added efficiency of 21%. The output power at −1 dB gain compression (P1dB ${P}_{1dB}$) is 40.2 dBm, and the power density is up to 3.36 W/mm in the active periphery under the drain voltage of 24 V. The chip is compact with an area of 5.6 × 3.7 mm2. This PA achieves higher output power in comparison to the reported PA MMIC. [ABSTRACT FROM AUTHOR]

This letter presents a 0.01–50‐GHz resistive matching power detector implemented in a commercial 0.15‐μm $\mathrm{\mu m}$ GaAs pseudomorphic high electron mobility transistor technology. An analytical expression is derived for the voltage responsivity of the detector as a function of temperature. To compensate for the temperature dependence of the detector, bias diode topology and mesa resistor load are employed. For an input power of −20 dBm at 1 GHz, the maximum variation of the detector output voltage is less than 0.5 dB over the temperature from −55° $-55^\circ $C to 85° $85^\circ $C. The detector's S11 is less than −8 dB, the dynamic range (DR) is 55 dB, and the maximum voltage responsivity is 700 V/W. An on‐chip wideband capacitor with a bent‐strip shape is designed for direct current blocking. The detector can be used for wideband power monitoring and power amplifier control loop for its high DR and temperature stability. [ABSTRACT FROM AUTHOR]

In this paper, a sparse smooth twin support vector regression (Sparse‐STSVR) model for power amplifier (PA) behavioral modeling is obtained by pruning the kernel matrix based on Cholesky decomposition. Based on the primal smooth twin support vector regression (STSVR) model, the Nystrom approximate matrix of the kernel matrix is found to replace the original kernel matrix, thus simplifying the Newton iterative parameter extraction process of the primal STSVR model and accelerating the convergence of the algorithm. In addition, the new rank approximation kernel matrix has the characteristic of sparse parameters, which further reduces the computational complexity of the feedforward link of the digital predistorter. The 100 MHz 5G New Radio (NR) signal is used for verify the effect of PA modeling and digital predistortion (DPD) experiment. The results show that the proposed method can improve the normalized mean square error (NMSE) by about 2 ~ 3 dB with fewer coefficients compared with the previously proposed machine learning model, and the predistortion linearization effect improves by nearly 3 dB on the adjacent channel power ratio (ACPR), which achieves a good trade‐off between model performance and computational complexity. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive overview of Gallium nitride (GaN)-based power amplifier (PA) design for various frequency bands. GaN-based technology has emerged as a promising alternative to traditional silicon-based amplifiers due to its superior performance characteristics, which are discussed in this paper. This paper also discusses the key design parameters and challenges associated with PA design. Various design techniques and topologies for GaN power amplifiers are explored besides addressing theoretical considerations of PA design along with a complete systematic design procedure for L-Band amplifier using the wolfspeed large signal GaN HEMT model. To further demonstrate the useful methodology, the designs of S-band and C-band PAs are also presented. GaN-based devices are very promising candidates for high-power applications. It is widely used in various high-power applications including communication and radar. [ABSTRACT FROM AUTHOR]

This paper conducts a validation of two linearization approaches that utilize baseband nonlinear linearization signals of the 2nd order, through practical experiments on an asymmetrical two-way microstrip Doherty amplifier (ADA), and simulations on a symmetrical two-way Doherty amplifier (DA) as well as the single stage power amplifier (PA) for the post-OFDM 5G modulation formats. In the first approach, linearization signals are led at the input and output of the carrier transistor in the DA, while in the second approach, they are injected at the outputs of both the carrier and peaking amplifiers. The DA was tested in simulation for the FBMC signal of 20 MHz bandwidth, while the experimental measurements were performed for the FBMC signal on the ADA for different useful signal frequency bandwidths, 5 MHz, 7.5 MHz, and 10 MHz. The maximal improvement of DA linearity obtained in simulation is 10 dB for lower power and 5 dB for maximum amplifier output power, while the second approach gives around 2 dB better results for higher power levels. The experimental test for ADA performed for considered signal bandwidths indicates 3 dB to 5 dB linearity improvement for the implemented approaches and more symmetrical results achieved by the second approach. Additionally, the simulation tests for the PA were carried out for the FBMC, UFMC, and FOFDM signals of 100 MHz bandwidth, with the application of the first linearization approach. The minimal achieved linearization improvement is 13 dB for the FOFDM signal and a maximal of 18 dB for the FBMC signal. [ABSTRACT FROM AUTHOR]

This paper presents a novel hybrid Class-E/FJ power amplifier (PA) that integrates Class-E/F PA and Class-J PA to formulate a high-efficiency as well as broadband performance. The theoretical relationships of the Class-E/F amplifier have been thoroughly examined, and the corresponding relationships and diagrams have been obtained. Furthermore, in the next step, theoretical analysis for Class-J has been derived, and the necessary conditions for achieving a strengthening relationship between Class-E/F and Class-J to achieve a hybrid Class-E/FJ PA have been investigated. Through the judicious configuration of parameter values, the proposed design achieves an efficiency range spanning from 61.2% to 73.4% across the 1.3-3.1 GHz. The paper delineates a systematic design process for a broadband Class-E/FJ PA based on derived theories. To validate the proposed approach, a meticulous design and fabrication process is undertaken for a 1.3-3.1 GHz broadband Class-E/FJ PA. Measurement results demonstrate that the PA can deliver a saturated output power ranging from 39.3 dBm to 42 dBm, accompanied by a gain within the 8-12 dB range. Additionally, the Power Added Efficiency (PAE) falls within the range of 58.9%-67% within the specified frequency band. A comparative analysis with similar predecessors reveals that the proposed PA outperforms others, exhibiting superior performance across a wide bandwidth. [ABSTRACT FROM AUTHOR]

Today’s era is a digital world where each and every section of the society is experiencing and encountering with semiconductor chips. In very large-scale integration (VLSI) circuits the design of static random-access memory (SRAM) plays a crucial role in ensuring both low-power consumption and high-speed performance. The sense amplifiers (SA) are integral parts for information accessing storage in SRAM IC design. This paper introduces a dual voltage latch sense amplifier (DVLSA) for SRAM integrated circuits (IC). The comparative analyses of various SA are studied and then design a low-power SA through the implementation of energy-efficient technique. Further, we have elucidated the causes of delay and power dissipation in different SA with useful solutions and performance evaluation is conducted by comparing the proposed design with existing SA reported in the literature. The performance parameters such as power 1.604 uw, energy 470.50 fJ, delay 80.04 ps, and current 5.406 are scrutinized to assess the efficiency of the designs. The cell outcomes have been validated with cadence tool on 180 nm technology and operate at 1.8 V. The proposed design, namely, DVLSA demonstrates minimal energy consumption and low power dissipation, making it a promising advancement in SRAM IC technology. [ABSTRACT FROM AUTHOR]

The polarization direction-dependent SBS threshold was investigated, and the terminal polarization control technique was demonstrated to restore the linear polarization state. By increasing the relative angle of the injecting polarization direction from 0° to 90°, the measured SBS threshold increased until reaching a maximum value, beyond which it decreased in a nearly symmetrical trend. The highest SBS threshold was achieved with the relative polarization angle being 45°, delivering a 67% threshold enhancement compared with that at 0°. A quarter-wave-plate was used to restore the polarization state of the output laser manually from an elliptic to a linearly polarized state, and temperature-dependent polarization fluctuation was observed, which intensified as the laser power was scaled. By reducing the cooling temperature, a 1 kW laser with a linearly polarized state was demonstrated using a 45° polarization direction-injected monolithic PM amplifier. [ABSTRACT FROM AUTHOR]

In this study, a millimeter-wave far-field range antenna measurement system is proposed for W-band monopulse antenna measurements. Since the W-band monopulse antenna installed in radar systems has many input/output ports, multiple calculations are required to measure all the ports. We propose a system structure capable of the simultaneous measurement of multiple channels to quickly and accurately measure the performance of a monopulse antenna. The proposed measurement system includes a multi-channel rotary joint, a pair of diplexers, and multiple vector network analyzer extenders. In addition, an RF sub-system is implemented to reliably measure the phase of the W-band radiation pattern. It utilizes a shared local oscillator source and external power amplifiers for the transmit and receive paths. Employing the proposed multi-channel antenna measurement system, the sum/difference channels of a monopulse antenna were simultaneously measured according to the azimuth angle. In addition, a comparison of the far-field measurements provided by the proposed system and the near-field measurements was conducted. [ABSTRACT FROM AUTHOR]

This review paper examines the advancements in solid-state power amplifiers (SSPAs) for wireless communication technology. As mobile devices rely on efficient power amplifiers to maintain battery life and ensure clear signal transmission, fabrication technologies like complementary metal–oxide–semiconductor (CMOS) and gallium nitride (GaN) are revolutionizing power amplifier (PA) design. The choice of material depends on the working frequency, with gallium arsenide (GaAs) and GaN suitable for frequencies under 100 GHz, and indium phosphide reaching up to 500 GHz. However, cost is a crucial factor in industrial manufacturing, making CMOS technology advantageous for on-chip system integration. Millimeter-wave chips have different requirements based on their application scenarios. In the Ka-band (26.5–40 GHz), high-power GaN and GaAs chips are preferred for satellite and long-distance communication. In contrast, the 60 GHz band is suited for short-distance high-speed communication and consumer electronics, making lower-cost CMOS and germanium silicon devices the preferred choice. This paper explores critical design considerations for SSPAs, focusing on common structures like envelope tracking, Doherty amplifiers, envelope elimination and restoration, and various linearization methods. We provide a clear comparison of their strengths and weaknesses to empower readers to select the optimal SSPA structure for their needs. Our review aims to facilitate informed decisions in the development of efficient and cost-effective SSPAs for advancing wireless communication technology. [ABSTRACT FROM AUTHOR]

This paper studies the influence of the gate voltage of the power amplifier (PA) on the drain current and efficiency. This study proposes a theory of controlling input non‐linearity to improve the efficiency of PAs. The theoretical efficiency of the inverse Class F PA that controls the input nonlinearity is within the range of 77% to 97%. A new design method for the inverse Class F PA reconstructs the design of the load admittance space into a region instead of a point. To verify the validity of the proposed theory, an inverse Class F PA is designed and fabricated using a commercial 10 W GaN high electron mobility transistor (HEMT). Results of the measurement show a high drain efficiency (DE) of 78.5%, an output power of 41.6 dBm, and a large signal gain of 12.1 dB at 1.5 GHz. The overall PA's size is controlled at 80*50 mm2$$ \mathrm{m}{\mathrm{m}}^2 $$. [ABSTRACT FROM AUTHOR]

In this article, a systematic theory and design approach are presented to achieve bandwidth expansion of the Doherty power amplifier (DPA) by using extended continuous Class‐GF (ECCGF) power amplifiers (PAs) as carrier PAs. The results of the theoretical analysis indicate that compared to conventional DPA, introducing ECCGF PA as carrier PA into the DPA design can establish two larger target impedance spaces with overlapping regions for saturation and output back‐off (OBO) power levels, which can reduce the design complexity of impedance inverter networks (IINs) while achieving DPA bandwidth expansion. Based on this, the proposed design theory is validated in the design and fabrication of a prototype DPA employing the CGH40010F GaN HEMT provided by MACOM. The measured results show that under continuous wave excitation, the designed DPA delivers a saturated output power of 43.1–44.2 dBm in the range of 1.3–2.7 GHz with a relative bandwidth of 70%. The drain efficiencies of 61.2%–73.2% and 42.5%–52.7% are achieved over the entire band at the saturation and 6‐dB OBO power levels, respectively. The measured results also confirmed the theoretical findings. [ABSTRACT FROM AUTHOR]

In this paper, behavioral modeling of a driver amplifier is implemented by using S2P and S2D model setup. By using the standard silicon-based driver amplifier for obtaining the measured results of Scattering (S)- parameters and large signal parameters for temperatures 25°C and 85°C. These parameters are imported into the S2P and S2D models to perform the small signal and large signal analysis at 3 GHz frequency for temperatures 25°C and 85°C. Then, the simulated results are compared with the measured results to verify the efficient utilization of behavioral models. The novelty of this work deals with the simulation study of the characteristics of a silicon-based driver amplifier, which are obtained directly from the measurements. This proposed method is essential for performing hetero-integration of transceiver design, which can be further utilized to improve the efficiency of transceiver for high-frequency band. At last, the study of relative error performance analysis between measured and simulated results of different parameters is carried out and calculated value of NMSE (in %) for S11, S12, S21, S22, gain, pout, 1 dB compression point, ACP, 3rd harmonics, 4th harmonics, and 5th harmonics are 0.0083, 0.0055, 0.0086, 0.011, 0.0844, 0.814, 0.926, 0.71, 0.22, 0.012 and 0.070 respectively. [ABSTRACT FROM AUTHOR]

The design of a single chip current source based on a common power operational amplifier is presented and demonstrated for the purpose of controlling applied magnetic fields using bias/shim electromagnets in cold atom experiments. The efficacy of the design is realized via application to red-detuned polarization-gradient cooling of 87Rb down to 3 μK. Furthermore, we demonstrate Raman spectroscopy using these devices to apply current and so generate a precise, accurate, and reproducible magnetic field. This work is intended as a short tutorial for new graduate students and postdocs of laser cooling and trapping. [ABSTRACT FROM AUTHOR]

Summary: The small signal modeling, design, fabrication, and measurement about monolithic millimeter‐wave integrated circuit (MMIC) using gallium nitride (GaN) power amplifier (PA) on silicon carbide (SiC) working at the E band are proposed in this paper. The two stage PA used customized 4 × 75 μm transistor with 100 nm T gate technology. The extraction and optimization of small signal model are based on single GaN high electron mobility transistor (HEMT)'s measurement. Balanced structure and new method are used by low impedance matching, which can simplify circuits prominently and benefit for die size reduction. Radial stub and LC stub are made the whole circuit in absolute stable status; the in‐series DC block metal–insulator–metal capacitor from the matching circuit ensure the process is within small tolerances. From the 61–66 GHz bandwidth, a peak 10.7 dB small signal gain is obtained from the designed MMIC GaN PA, and also, the maximum output power can reach 29.7 to 30.4 dBm from 61 to 66 GHz, with an associated the peak drain efficiency of 18.8%. The final die size without dicing slot is 3.0 × 1.74 mm2. [ABSTRACT FROM AUTHOR]