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A survey on ultra-wideband complementary metal-oxide semiconductor (CMOS) power amplifiers for wireless body area network (WBAN) applications is presented in this paper. Formidable growth in the CMOS integrated circuits technology enhances the development in biomedical manufacture. WBAN is a promising mechanism that collects essential data from wearable sensors connected to the network and transmitted it wirelessly to a central patient monitoring station. The ultra-wideband (UWB) technology exploits the frequency band from 3.1 to 10.6 GHz and provides no interference to other communication systems, low power consumption, low-radiated power, and high data rate. These features permit it to be compatible with medical applications. The demand target is to have one transceiver integrated circuit (IC) for WBAN applications, consequently, UWB is utilized to decrease the hardware complexity. The power amplifier (PA) is the common electronic device that employing in the UWB transmitter to boost the input power to the desired output power and then feed it to the antenna of the transmitter. The advance in the design and implementation of ultra-wideband CMOS power amplifiers enhances the performance of the UWB-transceivers for WBAN applications. A review of recently published CMOS PA designs is reported in this paper with comparison tables listing wideband power amplifiers' performance. [ABSTRACT FROM AUTHOR]

In this Letter, a wireless transmitter using the new architecture of programmable metasurface is presented. The proposed transmitter does not require any filter, nor wideband mixer or wideband power amplifier, thereby making it a promising hardware architecture for cost‐effective wireless communications systems in the future. Using experimental results, the authors demonstrate that a programmable metasurface‐based 8‐phase shift‐keying (8PSK) transmitter with 8 × 32 phase adjustable unit cells can achieve 6.144 Mbps data rate over the air at 4.25 GHz with a comparable bit error rate performance as the conventional approach without channel coding, but with less hardware complexity. [ABSTRACT FROM AUTHOR]

RF/microwave power amplifier (PA) is one of the components that has a large effect on the overall performance of communication system especially in transmitter system and their design is decided by the parameters of transistor selected. This letter presents a new concept of a wide-band microwave amplifier using scattering parameters that is often used in the radio frequency communication systemas an application of the active integrated antenna[1- 2]. This power amplifier operates from 1.75 GHz to 2.15GHz frequency and it is based on AT-41410 NPN transistor that has a high transition frequency of 10GHz. The proposed Single Stage PA is designed by microstrip technology and simulated with Advanced Design System (ADS) software. The simulation results indicate good performances; the small power gain (S21) is changed between 11.8 and 10dB. For the input reflection coefficient (S11) is varied between -11 and - 22.5dB. Regarding the output reflection coefficient (S22) is varied between -13.1 and -18.7dB over the wide frequency band of 1.75-2.15GHz and stability without oscillating over a wide range of frequencies. [ABSTRACT FROM AUTHOR]

A purely passive design technique for a class-J power amplifier (PA) is proposed, based on complex terminations at the fundamental frequency and the second harmonic, which increases the bandwidth while maintaining high efficiency. Using combined analytical derivation and numerical simulations, the drain impedance termination locus curve is obtained in the drain efficiency and DC voltage spaces. Successive application of the newly proposed de-normalization technique avoids the drain DC voltage manipulation used elsewhere. This is due to the resulting variable reactance of the output drain-source capacitor, optimal over a wide frequency range. Following the proposed procedure and the obtained optimal parametric space, a GaN HEMT-based PA is designed, fabricated, and tested displaying a very good agreement of the predicted and measured results. [ABSTRACT FROM AUTHOR]

A commercial 0.25 µm GaN process is used to implement 6-18 GHz wideband power amplifier (PA) monolithic microwave integrated circuits (MMICs). GaN HEMTs are advantageous for enhancing RF power due to high breakdown voltages. However, the large-signal models provided by the foundry service cannot guarantee model accuracy up to frequencies close to their maximum oscillation frequency (Fmax). Generally, the optimum output load point of a PA varies severely according to frequency, which creates difficulties in generating watt-level output power through the octave bandwidth. This study overcomes these issues by the development of in-house large-signal models that include a thermal model and by applying distributed L-C output load matching to reactive matched amplifiers. The proposed GaN PAs have successfully accomplished output power over 5 W through the octave bandwidth. [ABSTRACT FROM AUTHOR]

A near‐band digital predistortion technique is proposed to linearise a wideband power amplifier (PA) with millimetre wave (mmWave) non‐contiguous carrier aggregation (CA). The proposed method employs low‐bandwidth linearisation architecture to only focus on the in‐band compensation and part of the out‐of‐band (OOB) distortion suppression, which largely alleviate the bandwidth limitation for baseband operation. Experiments have been carried out on an mmWave PA with the centre frequency of 41 GHz. Good measurement results can be achieved when the PA is excited by a very wideband modulated signal with 1001 CA configuration and the total bandwidth of 640 MHz. [ABSTRACT FROM AUTHOR]

ABSTRACT In this article, a systematic design approach for a Class-A operated wideband power amplifier is presented. The power amplifier structure comprises of two transistors in the cascaded single stage traveling wave amplifier topology. A power amplifier was designed by using the systematic approach and fabricated with 0.25 μm GaAs PHEMT MMIC process. The amplifier has an area of 3.4 × 1.4 mm2. Measurement results show that almost flat gain performance is obtained around 15 dB over 1.5-9 GHz operating bandwidth. In most of the band, with the help of a wideband load-pull matching technique, the amplifier delivers Po,sat and Po,1dB of around 30 dBm and 28 dBm where the corresponding power added efficiencies are >50% and >36%, respectively. It is shown that the proposed design approach has the advantage of simple and systematic design flow and it helps to realize step-by-step design for the designers. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:615-622, 2014. [ABSTRACT FROM AUTHOR]

This letter presents a Ka-Band 0.1-\mu\textm GaAs pHEMT Power Amplifier with broad bandwidth. The isolating backvia wall (IBVW) has been proposed to improve the stability and performance. Over the frequency band of 31–40 GHz, implemented PA delivers 5 W saturated output power, 28% maximum power added efficiency (PAE) and 20 dB maximum small-signal gain. The chip size of the PA is 11.9 mm2. To the best of authors knowledge, the presented PA demonstrates widest bandwidth in Ka-band GaAs PAs while maintaining compact size. [ABSTRACT FROM PUBLISHER]

The requirements of two‐way radio applications in the wideband operating frequency are stringent, particularly for the power amplifier (PA) design. A novel design method for a wideband PA matching network for two‐way radio applications is proposed. The design method begins with identifying an initial guess of the matching network from the theoretical analysis, followed by a practical design methodology to realise the design in the compact form factor and low cost implementation. Experimental results demonstrated an output power of ∼7 W and an efficiency of about 65%, demonstrated high power performance (including stable operation and ruggedness) from 270 to 560 MHz running at a low DC supply of 7.2 V (with LDMOS device technology). [ABSTRACT FROM AUTHOR]

Demonstrated is a 2–4 GHz wideband power amplifier (WPA) using Cree 10 W GaN HEMT CGH40010. Also a novel process to find the optimum impedances is presented, with which the gain flatness can be taken into account. A compact PCB has been fabricated and tested with continuous waves at low (20 dBm) and high (28 dBm) input power level. From the measured results, at low power level, the gain is 13.1–14.1 dB across 2.0–3.9 GHz and 12.3–14.1 dB across 2.0–4.0 GHz. For large signals, power gain is 11.1–12.6 dB with power‐added efficiency (PAE) 36.5–53.4% while output power is around 40 dBm. Gain flatness keeps less than 1 dB beyond 95% of the band. For a 5 MHz WCDMA signal, the adjacent channel leakage ratio of the WPA with digital predistortion reaches − 45.3 dBc with an average drain efficiency of 46.7%. [ABSTRACT FROM AUTHOR]