High-efficiency GaN class-E power amplifier with compact harmonic-suppression network

This paper presents a new class of power amplifier (PA) - Class-iF- <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> - resolving the highly nonlinear double inflection characteristics in the conventional Class-F- <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> PA. It is illustrated that, by properly terminating the second harmonic source impedance Z <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2S</inf> from conventional short-circuit to open-circuit, the double inflection nonlinear gain profile can be mitigated in the proposed Class-iF- <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> PA, wherein the same saturation output power is achieved with less gain compression without drain efficiency trade-off. The idea was validated with source/load-pull and a broadband prototype operating from 2.0 to 2.6 GHz was designed using a commercial 10-W Gallium Nitride (GaN) transistor. Under continuous wave (CW) signal test, the proposed Class-iF- <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> PA can achieve 40.1-40.8-dBm output power, 71.2%-77.3% drain efficiency (DE) and 67.4%-74.1 % power added efficiency (PAE) at 3-dB gain compression level over 2.0-2.6 GHz.

High efficiency Class-E Power Amplifiers (PA) are difficult to analytically design using the original design equations. We present a high frequency (HF) Class-E PA design methodology that simplifies design in this thesis. A high-efficiency Class-E PA was designed using a low-cost power FET by following this design-flow. Due to their small size, it’s difficult to design efficient MCR-WPT resonators for portable electronics. We propose a novel multi-layer MCR-WPT Printed Spiral Coil (PSC) design and design methodology. Two MCR-WPT PSC resonators were designed for smartphones and tablets to meet the Rezence Self-Resonant Frequency and efficiency specifications using this novel design and design methodology. The MCR-WPT resonators power transfer efficiency is reduced when their separation distance is below the optimal Critical Coupling Distance (CCD) due to frequency splitting. We present a novel maximum-peak detection and auto-tuning circuit that automatically improves efficiency using capacitive tuning when the separation distance is below the CCD.

In this paper, we present a high-efficiency S-band gallium nitride (GaN) power amplifier (PA). This amplifier is fabricated based on a self-developed GaN high-electron-mobility transistor (HEMT) with 10 mm gate width on SiC substrate. Harmonic manipulation circuits are presented in the amplifier. The matching networks consist of microstrip lines and discrete components. Open-circuited stub lines in both input and output are used to tune the 2nd harmonic wave and match the GaN HEMT to the highest efficiency condition. The developed amplifier delivers an output power of 48.5 dBm (∼70 W) with a power-added efficiency (PAE) of 72.2% at 2 GHz in pulse condition. When operating at 1.8–2.2 GHz (20% relative bandwidth), the amplifier provides an output power higher than 48 dBm (∼ 65 W), with a PAE over 70% and a power gain above 15 dB. When operating in continuous-wave (CW) operating conditions, the amplifier gives an output power over 46 dBm (40 W) with PAE beyond 60% over the whole operation frequency range.

본 논문에서는 접지 결함 구조(Defected Ground Structure: DGS)를 이용하여 기지국용 고효율 E급 전력 증폭기의 성능을 유지하면서 크기를 소형화 할 수 있는 방안을 제안하였다. E급 전력 증폭기에서 요구되는 고조파 임피던스는 아령형 DGS와 나선형 DGS를 사용함으로써 만족시켜 주었다. 제안하는 유사 E급 전력 증폭기의 DGS 부하 회로는 가장 큰 고조파 성분인 2차 고조파 대역에서 개방, 나머지 고차 고조파 임피던스는 단락에 가까운 고조파 임피던스를 갖는다. 제안하는 구조를 통하여 제작된 전력 증폭기는 출력 전력이 43.1 dBm, 포화전력 이득이 12.7 dB일 때 70.2 %의 전력 부가 효율(Power Added Efficiency: PAE)을 가지며, 이는 비교 대상인 E급 증폭기와 거의 유사한 값이다. 회로 크기의 관점에서 보면 각각의 고조파 성분 정합을 위해 여러 개의 스터브가 장착되어 있는 비교 대상인 E급 증폭기에 비해 전체 크기를 50 %로 소형화시킬 수 있었다. In this work, a reduced size 20W quasi class-E Power Amplifier(PA) with defected ground structure load-network is presented for WCDMA base station application. Harmonic impedances required for the class E operation are satisfied by applying the dumbbell and the asymmetric spiral DGS. Open impedance for 2nd harmonic frequency which has the highest power and nearly short impedances for other higher order harmonics are provided by the proposed DGS load-network. The maximum Power Added Efficiency(PAE) of 70.2 % at the output power of 43.1 dBm with the saturated power gain of 12.7 dB is achieved by the proposed quasi class-E PA, which is comparable to the performance of the reference class-E PA. Total size of the proposed class-E PA is only <TEX>$50{\times}50\;mm^2$</TEX> and much smaller than the conventional class-E PA that is loaded with a number of open stubs.

Gallium Nitride (GaN) HEMTs are the focus of intense research and development due to their potential for the realization of power amplifiers (PAs) with high gain and record levels of power delivery. Much of the work in GaN HEMT development has been concentrated on performance improvement, and the demonstration of exceedingly higher power densities (>10W/mm). To demonstrate this performance, the device is typically subjected to bias levels greater than 40V, which result in large electric field stresses in the vicinity of the gate. Additionally, junction temperatures greater than 250/spl deg/C are predicted for the corresponding density of dissipated power. There is a lack of a comprehensive understanding of the effect of these large electrical and thermal stresses on the aging and degradation of GaN devices. There has only been a limited number of reports on the stability of GaN devices over time under RF dirve. In the present paper, we investigate the stability of GaN/AlGaN HEMTs under RF and DC stress. We provide a first look at the behavior of the device output power, quiescent currents, and leakage currents as a function of time under variable RF and DC stress conditions.

A cascode configuration in class-E CMOS power amplifiers (PAs) provides high reliability with respect to breakdown considerations. However, it causes a power loss due to the slow transition of a common-gate device from the triode region to the cut-off region. To minimize the power loss of cascode class-E CMOS PAs, we propose a charging acceleration technique, CAT. This method incorporates a capacitive element between the drain and the source of a common-gate device in a cascode configuration, accelerating the charging speed responsible for turning off a common-gate device instantly after a common-source device is turned off and thus minimizing power loss from the device. We compared the performance of the proposed cascode class-E PA to that of the conventional cascode class-E PA using a 0.18- CMOS process. With a 3.3-V power supply, the proposed fully-integrated CMOS PA achieves 30.7 dBm of maximum output power and 45.6% of power-added efficiency (PAE) with a dynamic range of 40 dB at 1.6 GHz. According to measurements, the proposed cascode class-E PA shows improvement in PAE over the conventional class-E PA of between 5% and 9% in a 1.5 to 2.0 GHz range.

A two-stage power amplifier (PA) using GaN HEMTs is presented with a high power added efficiency (PAE) and good linearity. This PA employs a structure of a class-C PA driving a class-AB PA to obtain a high PAE while maintaining the linearity. Source-pull and load-pull techniques were implemented to achieve optimum output impedance and inter-stage matching condition to compromise the PAE and the linearity of the overall circuit. When producing a two-tone carrier-to-intermodulation (C/I) ratio of 30 dB with the 1 MHz space, the two-stage PA exhibits a maximum PAE of 47% with an output power of 3 W at 3.7 GHz. The PA provides a maximum output power of 7 W with the gain of 15.8 dB.

This paper presents the design of a Gallium Nitride (GaN) transistor-based ultra-wideband (UWB) high-efficiency power amplifier (PA) with 25W (44 dBm) output power operating in the 2–6 GHz frequency band. The design of the matching circuits is based on a simplified systematic approach utilizing the target impedance trajectory. The Macom CGHV1F025S model GaN transistor and Rogers RT5870 model substrate are used in the design. The experimental results show that performance of the implemented PA offers 9.8 dB power gain, 43.8 dBm output power, and power-added efficiency (PAE) between 41% and 57% in the 2–6 GHz band. Cite this article as: E. Çağdaş, O. Kızılbey, and M. Yazgı, "Ultra wideband high efficiency high power amplifier design by simplified output matching technique," Electrica, 24(3), 755-766, 2024.

The single event effect (SEE) and the total ionizing dose (TID) effect of a commercial enhancement mode gallium nitride (GaN) high electron nobility transistor (HEMT) with p-type gate structure and cascode structure are studied by using the radiation of heavy ions and &lt;sup&gt;60&lt;/sup&gt;Co gamma in this paper. The safe operating areas ofSEE, the sensitive parameters degradation of TID effect and the SEE and TID characteristics of GaN HEMT device are respectively presented. The experimental results show that the SEE and TID effect have less influence on the p-type gate GaN device. The linear energy transfer (LET) threshold of the single event Burnout effect (SEB) is higher than 37 MeV·cm&lt;sup&gt;2&lt;/sup&gt;/mg and the failure threshold of TID effect is above 1M rad (Si) for p-type gate GaN device. However, the GaN HEMT device with cascode structure is much more sensitive to SEE and TID effect than p-type gate GaN device. Under heavy ions at LET of 22 MeV·cm&lt;sup&gt;2&lt;/sup&gt;/mg and a cumulative dose of 200 krad (Si), the SEB phenomenon and parameters-degradation of cascode-type GaN HEMT are respectively observed. Besides, the circuit structure of the cascode-type GaN HEMT device is analyzed by using metallographic microscope imaging and focused ions beam technology. It reveals the possible reason why it is sensitive to SEB and TID for cascode-type GaN HEMT. These results show that the extra carriers caused by heavy ion radiation can tunnel the Schottky barrier formed by gate metal and AlGaN layer, leading to a large source-drain current in GaN HEMT device. Meanwhile, it is shown that the metal oxide semiconductor field-effect transistor in cascode circuit for TP90H180PS GaN HEMT may be the main reason why the cascode-type GaN HEMT is sensitive to TID.

This article presents the design and validation for the high-efficiency class-E power amplifier (PA) that won first place in the high-efficiency PA for 475 kHz Student Design Competition held during the 2018 IEEE Microwave Theory and Techniques Society International Microwave Symposium (IMS 2018) in Philadelphia, Pennsylvania. Participants were required to implement and evaluate their own PAs. The team that achieved the highest drain efficiency while satisfying the conditions of the competition rules was the winner.

This paper presents a characteristic evaluation of commercial gallium nitride (GaN) transistors having two different gate-lengths of <TEX>$0.4-{\mu}m$</TEX> and <TEX>$0.25-{\mu}m$</TEX> in the design of a class-S power amplifier (PA). Class-S PA is operated by a random pulse-width input signal from band-pass delta-sigma modulation and has to deal with harmonics that consider quantization noise. Although a transistor having a short gate-length has an advantage of efficient operation at higher frequency for harmonics of the pulse signal, several problems can arise, such as the cost and export license of a <TEX>$0.25-{\mu}m$</TEX> transistor. The possibility of using a <TEX>$0.4-{\mu}m$</TEX> transistor on a class-S PA at 955 MHz is evaluated by comparing the frequency characteristics of GaN transistors having two different gate-lengths and extracting the intrinsic parameters as a shape of the simplified switch-based model. In addition, the effectiveness of the switch model is evaluated by currentmode class-D (CMCD) simulation. Finally, device characteristics are compared in terms of current-mode class-S PA. The analyses of the CMCD PA reveal that although the efficiency of <TEX>$0.4-{\mu}m$</TEX> transistor decreases more as the operating frequency increases from 955 MHz to 3,500 MHz due to the efficiency limitation at the higher frequency region, it shows similar power and efficiency of 41.6 dBm and 49%, respectively, at 955 MHz when compared to the <TEX>$0.25-{\mu}m$</TEX> transistor.

: A key component of microwave telecommunication systems is the power amplifier (PA). The design parameters of a communication system, such as link performance, power budget, and thermal design are typically driven by the power amplifier's linearity, output power, and efficiency. These design parameters of PA are the key to ensuring an efficient system because the PA is the most power-consuming circuit in the communication system. In an effort to have students involved in this research area, the International Microwave Symposium (IMS) sponsored by IEEE Microwave Theory and Technique Society (MTT-S) has introduced a High Efficiency Power Amplifier Design Competition. In this report, we present a 2.8-GHz, 5-W, highly efficient PA based on a wide bandgap gallium nitride (GaN) high electron mobility transistor (HEMT) device (CGH 40010f from CREE). The PA design was presented at the 2010 IMS Student Design Competition and achieved the competition goal of output power greater than 5 W with a measured power added efficiency (PAE) of 61% at 2.8 GHz.

This paper presents a CMOS inverter-like Class-D/E switching power amplifier (PA). The proposed amplifier operates in-between Class-E and Class-DE PAs. For proper operation of a Class-E PA, an RF choke (RFC) with large inductance value and high self-resonant frequency is necessary. A Class-DE PA does not require an RFC but requires a dead-time between OFF-ON transitions of the two switches. The proposed PA uses two complementary switches and requires neither an RFC nor a dead-time for its operation. For the same supply voltage and the load resistance, the voltage stress on each switching device in the proposed PA is less than the voltage stress in a Class-E PA. Design and simulation results of a prototype PA at 2.45 GHz with +20 dBm output power are presented.

In order to meet the requirements of high efficiency and broadband for the wireless communication system, a high efficiency and broadband gallium nitride power amplifier (PA) is designed and verified. Using the step-matching structure, its bandwidth has been improved. Furthermore, its input matching network is constructed by connecting several microband lines serially to reduce the matching Q value. Meanwhile, the harmonic control network is designed as the output matching network, which is built by a quarter-wave (λ/4) line open circuit and short circuit microwave lines in parallel. Thus, its drain efficiency (DE)can be improved. This design is simulated and tested at 2.2–3 GHz with the gallium nitride (GaN) process. After measuring, it attains an output power (Pout) of 39.5–41.5 dBm, Gain of 10.5–12.5 dB, DE of 65.1%–78.3% with power added efficiency (PAE) of 64.8%–76.2%.

종래의 LDMOS를 사용한 전력증폭기는 AB-급 및 도허티 방식으로 60MHz 대역폭의 협대역에서 55%의 효율을 보여주고 있으나, 기지국의 전력증폭 모듈의 RRH의 적용에 따라 100MHz이상의 대역확장과 60%이상의 고효율 전력증폭기를 요구하고 있으므로, 본 연구에서는 LDMOS FET를 이용한 J-급 전력증폭기를 설계하여 200MHz대역에서 60%이상의 고효율 특성을 나타내었다. 설계한 J-급 전력증폭기는 2차 고조파 부하가 순수한 리액턴스 성분만을 포함하고 작은 양호도 Q 값을 갖도록 출력단 정합회로를 최적화 시켰다. 측정결과 WCDMA 주파수 대역을 포함한 2.06~2.2GHz에서 연속파 신호를 입력하였을 때 62~70%의 전력 부가효율(PAE)의 특성을 갖는 10W급 J-급 전력증폭기를 구현하였다. Existing LDMOS power amplifier that used class-AB and doherty system shows 55% of efficiency in 60MHz narrow band. Because RRH has been applied to power amplifier at base station. It is required that over 100MHz expanded band and more than 60% high efficiency power amplifier. In this paper we designed class-J power amplifier using LDMOS FET which has over 60% high efficiency characteristic in 200MHz. The output matching circuit of designed class-J power amplifier has been optimized to contain pure reactance at second harmonic load and has low quality factor Q. As a measurement result of the amplifier, when we input continuous wave signal, we checked 62~70% of power added efficiency(PAE) in 2.06~2.2GHz including WCDMA frequency as a 10W class-J power amplifier.