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In this paper, a sub-1dB Low Noise Amplifier (LNA) with several gain modes, including amplification and attenuation modes required for the fifth and fourth generations (5G/4G) of mobile network applications, is proposed. Its current consumption is adaptive for every gain mode and varies to lower currents for lower amplifications due to the importance of current consumption for mobile network applications. The proposed LNA features an innovative architecture with a three-core input structure supporting multi-gain modes, achieving high gain and ultra-low noise performance. Additionally, the design integrates a cascade switching mechanism to ensure fast transitions between the gain modes and maintain operational stability. A reconfigurable input structure is introduced to support multiple input stages, enabling the proposed LNA to be compatible with both 5G and 4G applications. The proposed design demonstrates the implementation of seven distinct gain modes with a maximum current consumption of 11.68 mA, achieving proper input matching in each gain mode. The LNA delivers a maximum gain of 20.4 dB with a noise figure of 0.73 dB. Moreover, the most stringent mode switching condition achieved, the ON time, is as short as 1.295 µs, and the gain mode transition speed is an impressive 0.874 µs, ensuring extremely fast mode transitions. The proposed LNA occupies an area of 700 µm × 500 µm and is fabricated using a 65 nm FD-SOI process.

This study presents a low-cost digital compensator design for a flyback converter featuring a full digital feedback loop. This design replaces the traditional analog compensation circuit with a digital compensator, where the external resistance and capacitor are removed. The system parameters of the digital compensator are engineered to allow for universal adaptability. An 8-bit successive-approximation analog-to-digital converter circuit facilitates the conversion of analog signals into digital data. These circuits are fabricated using a 180-nm BCD processor. The output voltage ranges from 3.5 to 9 V, while the output current varies from 1 to 3 A. The flyback converter equipped with the designed digital compensator achieves a maximum power efficiency of 83%. The total chip area, encompassing both the digital compensator and data converter circuit, measures $950~\mu $ m $\times 460~\mu $ m.

This paper proposed a fine dust detection system using time-interleaved counters in which surface acoustic wave (SAW) sensors changed the resonance point characteristic. When fine dust was applied to the SAW sensor, the resonance point decreased. The SAW oscillator made of the SAW sensor and radio frequency (RF) amplifier generated an oscillation frequency that was the same as the resonance frequency. The oscillation frequency was transferred to digital data by a 20-bit asynchronous counter. This system has two channels: a sensing channel and a reference channel. Each channel has a SAW oscillator and a 20-bit asynchronous counter. The difference of the two channel counter results is the frequency difference. Through this, it is possible to know whether fine dust adheres to the SAW sensor. The proposed circuit achieved 0.95 ppm frequency resolution when it was operated at a frequency of 460 MHz. This circuit was implemented in a TSMC 130 nm CMOS process.

This paper presents the design of a low-noise amplifier (LNA) with a bypass mode for the n77/79 bands in 5G New Radio (NR). The proposed LNA integrates internal matching networks for both input and output, combining two LNAs for the n77 and n79 bands into a single chip. Additionally, a bypass mode is integrated to accommodate the flexible operation of the receiving system in response to varying input signal levels. For each frequency band, we designed a low-noise amplifier for the n77 band to expand the bandwidth to 900 MHz (3.3 GHz to 4.2 GHz) using resistive–capacitance (RC) feedback and series inductive-peaking techniques. For the n79 band, only the RC feedback technique was employed to optimize the performance of the LNA for its 600 MHz bandwidth (4.4 GHz to 5.0 GHz). Because wideband techniques can lead to a trade-off between gain and noise, causing potential degradation in noise performance, appropriate bandwidth design becomes crucial. The designed n77 band low-noise amplifier achieved a simulated gain of 22.6 dB and a noise figure of 1.7 dB. Similarly, the n79 band exhibited a gain of 21.1 dB and a noise figure of 1.5 dB with a current consumption of 10 mA at a 1.2 supply voltage. The bypass mode was designed with S21 of −3.7 dB and −5.0 dB for n77 and n79, respectively.

This paper presents a wide-band multi-level switched mode class-E/F23 Power Amplifier (PA) with a reconfigurable power stage core transistor and a load with reconfigurable reactance compensation part. An Automatic Calibration Scheme (ACS) is proposed to perform the core and load reconfiguration based on a proposed algorithm. The PA is formed by a class-D driver amplifier, the switched mode cascaded reconfigurable power stage, the reconfigurable class-E/F23 load, the ACS and its algorithm, and the matching network at the end of the load before the antenna. The proposed PA is implemented using a 130 nm CMOS technology. The wideband PA operates in the frequency range from 470 MHz to 690 MHz for a TV White Space (TVWS) application with 220 MHz bandwidth. Even though reaching a high maximum Power Added Efficiency (PAEmax) for the design with low output powers is challenging a PAEmax of 32% for a 10 dBm output power level from a low supply voltage of 2.2 V. The proposed ACS provides an output power with a flatness around 0.6 dB which shows 57% improvement in compare with the structure without the ACS. The PA achieved a selectable multi-level output power from 10 dBm to 14 dBm over the 220 MHz bandwidth.

This paper presents a low-noise amplifier (LNA) with an integrated input and output matching network designed using RF-SOI technology. This LNA was designed with a resistive feedback topology and an inductive peaking technology to provide 600 MHz of bandwidth in the N79 band (4.4 GHz to 5.0 GHz). Generally, the resistive feedback structure used in broadband applications allows the input and output impedance to be made to satisfy the broadband conditions through low-impedance feedback. However, feedback impedance for excessive broadband characteristics can degrade the noise performance as a consequence. To achieve a better noise performance for a bandwidth of 600 MHz, the paper provided an optimized noise performance by selecting the feedback resistor value optimized for the N79 band. Additionally, an inductive peaking technique was applied to the designed low-noise amplifier to achieve a better optimized output matching network. The designed low-noise amplifier simulated a gain of 20.68 dB and 19.94 dB from 4.4 to 5.0 GHz, with noise figures of 1.57 dB and 1.73 dB, respectively. The input and output matching networks were also integrated, and the power consumption was designed to be 9.95 mA at a supply voltage of 1.2 V.

This paper presents a 0.46 mW and 2.4 GHz; All-Digital Phase-Locked Loop (ADPLL) through an Injection-Locked Frequency Multiplier (ILFM) and Continuous Frequency Tracking Loop (CFTL) circuitry for low power Internet-of-Thing (IoT) applications. In the proposed ADPLL architecture to save power, the need for Time-to-Digital Converter (TDC) is eliminated through providing the CFTL circuitry. This feature makes the design compact, low power, and suitable for IoT applications. The proposed design is based on a synthesizable pulse injection and frequency-locked loop along with an ultra-low-power LC Digitally-Controlled Oscillator (LC-DCO). The presented CFTL circuit adjusts the frequency of the DCO continuously and prevents the frequency drift after the reference injection. Inside the designed LC-DCO core, the power consumption is minimized by optimizing the $\text{g}_{\mathrm {m}}~/\text{I}_{\mathrm {D}}$ and adjusting the power supply to 0.5 V. The proposed ILFM based ADPLL is fabricated in 55 nm CMOS technology and covers the operational frequency range of 2.402 GHz to 2.480 GHz with a reference frequency of 32 MHz. The measured phase noise performance of the ADPLL is −111.15 dBc/Hz at 1 MHz offset frequency from the carrier frequency of 2.4 GHz. It consumes only 0.46 mW power with an active area of 0.129 mm2.

A 12-bit 80 MS/s hybrid type analog-to-digital converter (ADC) for high sampling speed and low power applications is presented in this paper. It has a subranging architecture with a front end of 6-bit Flash ADC with five channels of 6-bit time interleaved synchronous Successive Approximation Register (SAR) ADC. The proposed architecture with a shared 6-bit Flash ADC and time interleaved SAR ADC provides a power and area efficient high speed ADC. The proposed Time-skew calibration is implemented to minimize the discrepancy between the output of Flash ADC and SAR ADC’s channels. To rectify the decision error of the Flash ADC and extract the time-skew information, 1-bit redundancy is included in the CDAC of the SAR conversion. The decision error between the Flash ADC and the SAR ADC is covered with designed redundancy and the mismatch between the ADCs is covered with the time-skew calibration. To reduce the offset mismatch between Flash and SAR ADC and within SAR ADCs, all comparators are calibrated to minimize their absolute offset by utilizing background offset calibration. The modified dynamic strong ARM comparator is used for flash ADC and dynamic latched comparator is used for SAR ADCs. For fine offset calibration and low power consumption, the comparator’s offset calibration circuit is implemented. To reduce the kickback noise and enhance the overall energy efficiency for fast operation of SAR ADCs, rail-to-rail dynamic latch comparator with modified adaptive power control (APC) is implemented. The proposed ADC structure has been implemented in 130 nm CMOS process. The ADC has an effective number of bit (ENOB) of 10.97 bits while consuming 7.08 mW current consumption from the 1.2 V supply voltage.

This paper proposes a high-performance Digital Feedback low-dropout voltage regulator (DF-LDO) for low power applications. In the DF-LDO regulator, digital feedback and applying spectrum spread clock generator (SSCG) technique are used to reduce output voltage ripples. In addition, it has triple operation modes i.e. coarse, fine, and retention for high efficiency and transient enhancement. The proposed hybrid DF-LDO uses arrays of PMOS transistors in coarse and fine mode whereas in retention mode, only one comparator and NMOS are active and digital controller goes into the sleep mode. This results in the reduction of the power consumption and improves the output voltage ripples. In the retention mode, minimum number of blocks operate that reduces the current consumption as compared to coarse and fine modes. To further reduce the current consumption, the comparator with hysteresis is used. The proposed circuit is designed using CMOS 55 nm process. The input voltage range is from 0.8 ~ 1.5 V and the measured output voltage range is 0.756 ~ 1.456 V. The measured line regulation is 6 mV / V, and the regulation starts when the input voltage is 0.8 V. The measured load regulation is 2.3 mV/mA for maximum load current of 5 mA. The peak current efficiency of the proposed DF-LDO is 99.996 % with a maximum output voltage ripples value of 1.9 mV. The proposed digital LDO regulator active chip area is 0.012 mm2.

A proposed prototype of a 10-bit 1 MS/s single-ended asynchronous Successive Approximation Register (SAR) Analog-to-Digital Converter (ADC) with an on-chip bandgap reference voltage generator is fabricated with 130 nm technology. To optimize the power consumption, static, and dynamic performance, several techniques have been proposed. A dual-path bootstrap switch was proposed to increase the linearity sampling. The Voltage Common Mode (VCM)-based Capacitive Digital-to-Analog Converter (CDAC) switching technique was implemented for the CDAC part to alleviate the switching energy problem of the capacitive DAC. The proposed architecture of the two-stage dynamic latch comparator provides high speed and low power consumption. Moreover, to achieve faster bit conversion with an efficient time sequence, asynchronous SAR logic with an internally generated clock is implemented, which avoids the requirement of a high-frequency external clock, as all conversions are carried out in a single clock cycle. The proposed error amplifier-based bandgap reference voltage generator provides a stable reference voltage to the ADC for practical implementation. The measurement results of the proposed SAR ADC, including an on-chip bandgap reference voltage generator, show an Effective Number of Bits (ENOB) of 9.49 bits and Signal-to-Noise and Distortion Ratio (SNDR) of 58.88 dB with 1.2 V of power supply while operating with a sampling rate of 1 MS/s.

This paper presents an optimum layout method of a low-power, digitally controlled oscillator (DCO) for a Bluetooth low-energy (BLE) transceiver in a 4G/5G LTE system. For the optimal LC-based DCO layout, three different layouts, including different gm cell locations and an Al metal layer, were implemented, and performance was compared and verified for BLE application. The implemented neck DCO (NDCO), where the gm cell is located in the neck of the main inductor, showed superior performance compared to other layouts in terms of low phase noise and low power consumption. The designed NDCO had a low phase noise of −116.1 dBc/Hz at 1 MHz with a 0.5 mW power consumption. The supply voltage and oscillation frequency range were 0.8 V and 4.7–5.7 GHz, respectively, and the NDCO designed with the optimal layout had a good figure-of-merit of −192.6 dBc/Hz.

This paper presents an adaptive control and communication protocol (ACCP) for the ultra-low power simultaneous wireless information and power transfer (SWIPT) system for sensor applications. The SWIPT system-related operations depend on harvested radio frequency (RF) energy from the ambient environment. The necessary power for SWIPT system operation is not always available and it depends on the available RF energy in the ambient environment, transmitted RF power from the SWIPT transmitter, and the distance from the transmitter and channel conditions. Thus, an efficient control and communication protocol is required which can control the SWIPT system for sensor applications which mainly consists of a transmitter and a receiver. Multiple data frame structures are used to optimize the exchange of bits for the communication and control of the SWIPT system. Both SWIPT transmitter and receiver are capable of using multiple modulation schemes which can be switched depending on the channel condition and the available RF energy in the ambient environment. This provides support for automatic switching between the time switching scheme and power splitting scheme for the distribution of received RF power in the SWIPT receiver. It also adjusts the digital clock frequency at the SWIPT receiver according to the harvested power level to optimize the power consumption. The SWIPT receiver controller with ACCP is implemented in 180 nm CMOS technology. The RF frequency of the SWIPT operation is 5.8 GHz. Digital clock frequency at the SWIPT receiver can be adjusted between 32 kHz and 2 MHz which provides data rates from 8 to 500 kbps, respectively. The power consumption and area utilization are 12.3 µW and 0.81 mm².

In this article, a highly reliable radio frequency (RF) wake-up receiver (WuRx) is presented for electronic toll collection (ETC) applications. An intelligent digital controller (IDC) is proposed as the final stage for improving WuRx reliability and replacing complex analog blocks. With IDC, high reliability and accuracy are achieved by sensing and ensuring the successive, configurable number of wake-up signal cycles before enabling power-hungry RF transceiver. The IDC and range communication (RC) oscillator current consumption is reduced by a presented self-hibernation technique during the non-wake-up period. For accommodating wake-up signal frequency variation and enhancing WuRx accuracy, a digital hysteresis is incorporated. To avoid uncertain conditions during poor and false wake-up, a watch-dog timer for IDC self-recovery is integrated. During wake-up, the digital controller consumes 34.62 nW power and draws 38.47 nA current from a 0.9 V supply. In self-hibernation mode, its current reduces to 9.7 nA. It is fully synthesizable and needs 809 gates for its implementation in a 130 nm CMOS process with a 94 × 82 µm2 area. The WuRx measured power consumption is 2.48 µW, has −46 dBm sensitivity, and a 0.484 mm² chip area.

This paper presents a 612–1152 MHz Injection-Locked Frequency Multiplier (ILFM). The proposed ILFM is used to send an input signal to a receiver in only the I/Q mismatch calibration mode. Adopting a Phase-Locked Loop (PLL) to calibrate the receiver places a burden on this system because of the additional area and power consumption that is required. Instead of the PLL, to satisfy high-frequency, low-jitter and low-area requirements, a Ring Oscillator is adopted in the system. The free-running frequency of the ILFM is automatically and digitally calibrated to reflect the frequency of the injected signal from the harmonics of the reference clock. To control the frequency of the ILFM, the load current is digitally tuned with a 6-bit digital control signal. The proposed ILFM locks to the target frequency using a digitally controlled Frequency Locked Loop (FLL). This chip is fabricated using 1-poly 6-metal 0.18 µm CMOS and has achieved the wide tuning range of 612–1152 MHz. The power consumption is 0.95 mW from a supply voltage of 1.8 V. The measured phase noise of the ILFM is −108 dBc/Hz at a 1 MHz offset.

In this paper, a high noise immunity, 28 × 16-channel finger touch sensing IC for an orthogonal frequency division multiplexing (OFDM) touch sensing scheme is presented. In order to increase the signal-to-noise ratio (SNR), the OFDM sensing scheme is proposed. The transmitter (TX) transmits the orthogonal signal to each channels of the panel. The receiver (RX) detects the magnitude of the orthogonal frequency to be transmitted from the TX. Due to the orthogonal characteristics, it is robust to narrowband interference and noise. Therefore, the SNR can be improved. In order to reduce the noise effect of low frequencies, a mixer and high-pass filter are proposed as well. After the noise is filtered, the touch SNR attained is 60 dB, from 20 dB before the noise is filtered. The advantage of the proposed OFDM sensing scheme is its ability to detect channels of the panel simultaneously with the use of multiple carriers. To satisfy the linearity of the signal in the OFDM system, a high-linearity mixer and a rail-to-rail amplifier in the TX driver are designed. The proposed design is implemented in 90 nm CMOS process. The SNR is approximately 60 dB. The area is 13.6 mm2, and the power consumption is 62.4 mW.

State of the art machine learning methods can enhance the analysis of clinical data and improve the ability to predict patient outcomes because data collected from clinical records, such as heart failure mortality studies, are often high dimensional, heterogeneous and give challenges to traditional statistical analysis techniques. To address this challenge, this study conducted a survival analysis based on a dataset of 299 patients with heart failure, using Python libraries. Cox regression was used to model and analyse mortality, and to find which features are strongly associated with this outcome. The Kaplan-Meier survival curve approach was used to show the patterns of patient survival over time. The analysis showed that age, ejection fraction, and serum creatinine level were significantly (p≤0.001) associated with mortality. Anaemia and creatinine phosphokinase also reached statistical significance (p-values 0.026 and 0.007, respectively). The Cox model showed good concordance (0.77) with the data, suggesting that the identified variables are useful for predicting mortality in patients with heart failure. [ABSTRACT FROM AUTHOR]