1.8 GHz class E power amplifier for wireless communications

The authors present a 1.8 GHz class E power amplifier for wireless communications. A fully integrated class E power amplifier module was designed, fabricated and tested. The circuit was implemented in a self-aligned-gate, depletion mode 0.8 μm GaAs MESFET process. The amplifier delivers 23 dBm of power to the 50Ω load, with a power added efficiency of 57% at a supply voltage of 2.4 V     

IEEE 802.11a发射前端可变增益放大器和前置功率放大器的研究

本文介绍了用于单片集成IEEE 802.11a发射前端的5.2GHz可变增益放大器和前置功率放大器。本设计采用50GHz 0.35μm SiGe BiCMOS工艺,芯片面积为1.12×1.25mm2。可变增益放大器由5个控制字控制,可变增益范围为34dB,并在-30°C 到 85°C范围内具有较好的温度补偿效果。前置功率放大器采用差分输入、单端输出的结构,负载采用5.2GHz电感电容并联谐振电路。两个电路的总增益最大为29dB,OIP3为11dBm。在2.85V供电条件下,总功耗电流为45mA。     

5.2 GHz variable-gain amplifier and power amplifier driver for WLAN IEEE 802.11a transmitter front-end

A 5.2 GHz variable-gain amplifier (VGA) and a power amplifier (PA) driver are designed for WLAN IEEE 802.11a monolithic RFIC. The VGA and the PA driver are implemented in a 50 GHz 0.35 μm SiGe BiCMOS technology and occupy 1.12×1.25 mm2 die area. The VGA with effective temperature compensation is controlled by 5 bits and has a gain range of 34 dB. The PA driver with tuned loads utilizes a differential input, single-ended output topology, and the tuned loads resonate at 5.2 GHz. The maximum overall gain of the VGA and the PA driver is 29 dB with the output third-order intercept point (OIP3) of 11 dBm. The gain drift over the temperature varying from -30 to 85℃ converges within±3 dB. The total current consumption is 45 mA under a 2.85 V power supply.     

EER architecture specifications for OFDM transmitter using a class E amplifier

This letter presents envelope elimination and restoration (EER) architecture specifications in the case of orthogonal frequency division multiplex C band transmission. A key point is the recombination of envelope and phase information by supply modulation of the power amplifier (PA). Imperfections, such as time mismatch and phase noise can reduce the performances of the transmission. Compression and conversion effects when supply modulating the PA are introduced in this letter with the simulation of a class E power amplifier. This amplifier was designed under HP-ADS using a nonlinear MESFET model. Results are reported in terms of error vector measurement and spectrum for two different numbers of sub-carriers 32 and 128 in 16-QAM and 64-QAM cases.     

The class BD high-efficiency RF power amplifier

Class B and class D operation of the same RF power amplifier circuit is not normally possible because of constraints imposed by the tuned output circuit and DC power input circuit. The use of square-wave drive in a current switching class D RF amplifier circuit allows the amplifier to move gradually from current source to current switch operation. This amplifier, called class BD, has a linear transfer characteristic (drive envelope to output envelope) and an efficiency 1.23 times that of a class B RF amplifier with the same peak output. The addition of a resistive AC current path to ground in the DC power input circuit of the class BD RF amplifier allows operation with sinewave driving waveforms. While this lowers the efficiency at the peak output, it can raise it at lower outputs, making possible a factor of 1.57 improvement in efficiency in the amplification of signals with large peak-to-average ratios. The class BD RF amplifier may therefore be used as a broad-band replacement for a Doherty-type amplifier.     

A 1.75-GHz polar modulated CMOS RF power amplifier for GSM-EDGE

This work presents a fully integrated linearized CMOS RF amplifier, integrated in a 0.18-/spl mu/m CMOS process. The amplifier is implemented on a single chip, requiring no external matching or tuning networks. Peak output power is 27 dBm with a power-added efficiency (PAE) of 34%. The amplitude modulator, implemented on the same chip as the RF amplifier, modulates the supply voltage of the RF amplifier. This results in a power efficient amplification of nonconstant envelope RF signals. The RF power amplifier and amplitude modulator are optimized for the amplification of EDGE signals. The EDGE spectral mask and EVM requirements are met over a wide power range. The maximum EDGE output power is 23.8 dBm and meets the class E3 power requirement of 22 dBm. The corresponding output spectrum at 400 and 600 kHz frequency offset is -59 dB and -70 dB. The EVM has an RMS value of 1.60% and a peak value of 5.87%.     

声呐发射机中D类功率放大器的设计

声呐发射机的主要作用是产生具有特定形式的大功率电信号,经过匹配网络(提高发射机输出效率)后再通过换能器将电信号转换为声信号.发射机一般包括信号产生器、功率放大器和发射换能器.详细介绍了一种基于MOSFET的半桥式D类功率放大器设计的步骤和方法,并给出了水声换能器假负载的实验波形,信号畸变与失真较小.根据测试结果证明输出50 kHz左右PWM波时效率达到80％,符合声呐发射机高效率、小体积的设计要求.     

Phase-correcting feedback system for class E power amplifier

A phase-correcting feedback system which reduces the AM-to-PM distortion of Class E power amplifiers for wireless communication is presented in this paper. It comprises a novel limiting amplifier, a phase detector, and a phase shifter all operating at 835 MHz. The phase-correcting feedback together with a Class E power amplifier were fabricated in a 0.8-μm GaAs MESFET process. The limiting amplifier has a phase error less than 2.5°. The phase detector and phase shifter have a sensitivity of 10 mV/degree and 80°/V, respectively. The Class E power amplifier delivers 26.5 dBm to the load with a power added efficiency of 67%. The phase correcting feedback system reduces the 30° phase distortion of the Class E amplifier down to 4°, and its total power dissipation is 21.5 mW     

CDMA射频线性功率放大器

该文对前馈线性校正射频功率放大器进行了分析,给出了分析结果。并用该结果指导设计了CDMAIS-95基站射频线性功率放大器,放大器增益47dB,连续波输出功率60W,在通频带内三阶交调改善了23dB。     

E类功率放大器研究与应用

分析了E类功率放大器的工作原理,并基于此设计出一种高效高频E类功放,作为无线电能传输系统中发射级的前端驱动电路。运用LTspice仿真软件,对其基本原理电路进行实验分析。为进一步提升输出功率和传输效率,电路还加入了阻抗匹配。仿真结果表明,此电路可实现在6.78 MHz下以85%左右的高效率进行10~30W的功率传输,整体电路结构简单,有实用价值。     

UHF power amplifier of class E with a series forming circuit

The E-class mode of a power amplifier with a series (to the switch) forming circuit is investigated. An analysis of such an amplifier model is given. Formulas for the equivalent circuit elements are obtained. The load impedances of its switches on a fundamental frequency and on its harmonics are determined for the considered amplifier and for the device which forms a dual pair with it. The fundamental frequency compensation possibility for the capacitive part on the transistor switch output impedance is demonstrated. With the help of the described approach, the amplifier is developed for a frequency of 915 MHz with a drain efficiency of about 73.2% (PAE is about 71%) and the output power is about 7.32 W.     

一种24 GHz CMOS功率放大器设计

基于130 nm互补金属氧化物半导体(CMOS)工艺,设计了一种高增益和高输出功率的24 GHz功率放大器。通过片上变压器耦合实现阻抗匹配和功率合成,有效改善放大器的匹配特性和提高输出功率。放大器电路仿真结果表明,在1.5 V供电电压下,功率增益为27.2 dB,输入输出端回波损耗均大于10 dB,输出功率1 dB压缩点13.2 dBm,饱和输出功率17.2 dBm,峰值功率附加效率13.5%。     

Design of integrated 1.6 GHz, 2 W tuned RF power amplifier

This paper describes the design of an integrated tuned power amplifier specified to operate at Inmarsat satellite uplink frequencies from 1626.5 to 1660.5 MHz. The basic topology of the amplifier lies on the parallel tuned inverse class E amplifier that is modified by placing the DC-blocking capacitor into a new position and by adjusting the size of the capacitor to improve stability below the desired band. Further, the new positioning reduces losses between drain and load. The high currents flowing in the circuit made it necessary to use wide inductor width and high-Q finger capacitors in the on-chip resonator. The amplifier was implemented as a Gallium Arsenide (GaAs) integrated circuit (IC) that delivered 2 W of output power while the drain efficiency was ca. 56%. Measurements included source and load pulls to further improve the performance of the amplifier and to investigate the stability at small input drive levels.     

Junction-gate FET RF power amplifier

A junction-gate power field-effect transistor of recent design has been found to yield greater than 25 watts CW at 30 MHz in two modes of circuit configuration. In this investigation, favorable characteristics are explored for potential device utility as a high-reliability low-distortion RF power amplifier.     

应用于4G-LTE无线通信系统的F类高PAE射频功率放大器

为了有效实现高谐波抑制并提高功率附加效率,提出了一种适用于4G-LTE无线通信系统的高效F类功率放大器。该功率放大器使用了低电压p-HEMT晶体管和小型微带抑制单元,能够在低射频输入功率下产生n次谐波抑制和较高的功率附加效率（power added efficiency,PAE）。采用谐波平衡法对提出的功率放大器进行了仿真分析,并对其进行了实际制造。通过实际测量对仿真结果进行了验证。测量结果显示,提出功率放大器的工作频率为1.8 GHz,带宽为100 MHz,平均PAE为76.9％,且具有2V的极低漏极电压。射频输入功率范围分别为0-12 dBm时,最大输出功率和增益分别为23.4和17.5 dBm。     

射频功率放大器的建模

提出了运用模糊神经网络对射频功放电路进行建模的方法,模糊神经网络是近年来发展起来的一种新型的网络结构,具有万能函数逼近器的功能,文中用MATALAB中自带的自适应神经模糊系统ANFIS对仿真得到的数据进行建模,并利用得到的模型计算功放的频谱,功率压缩曲线,功率增益曲线,与ADS仿真的结果进行比较,取得了较好的结果,证明了建模方法的有效性.     

中波广播发射机功放问题处理与发射机维护研究

传统广播发射机存在着功能不足、耗电较大等缺陷,随着科技的发展,数字调幅中波发射机取得了较大的发展,取代了传统广播发射机。但中波广播发射机的功放问题,会影响了广播节目的播出质量。文章围绕中波广播发射机功放问题进行分析,并总结了发射机的维护技巧。     

高效率E类射频功率放大器

研究了E类RF放大器的电路结构、工作原理、存在问题以及解决的方法--差分和交叉耦合反馈结构,最后给出了E类放大器的实例.由于具有低成本、高集成度、多功用等优点,MOS工艺在射频功率放大方面有很大的发展潜力.在本文中,用0.6 u m CMOS工艺实现了E类放大器的设计.     

移动终端射频功放的动态电源管理与控制

本文研究WCDMA移动终端射频功放供电效率问题.分析了射频功放特性和电池放电特性,给出了考虑射频输出功率分布的动态电源管理方案和控制算法,分析结果表明:与常规的电池直接供电方案相比较,按照移动终端在城市的发射功率分布模型,新方案射频功放所需的平均功率降低了3.5倍,可以大大延长手机通话和待机时间.