一种具有电阻-电容补偿网络的宽带输出匹配电路  

Broadband common-collector output buffer with resistance and capacitance compensation network

作　　者：王钟[1] 严唯敏[2] 张晓东[4] 吴浩东[1] 高怀[3,4] 

机构地区：[1]南京大学近代声学重点实验室,南京210093 [2]苏州大学应用技术学院机电工程系,苏州215325 [3]东南大学国家专用集成电路系统工程技术研究中心,南京210096 [4]苏州工业园区教育发展投资有限公司,苏州英诺迅科技有限公司射频功率器件及电路技术中心,苏州215321

出　　处：《南京大学学报（自然科学版）》2010年第4期372-378,共7页Journal of Nanjing University（Natural Science）

摘　　要：本文提出了一种带有电阻-电容(RC)补偿网络的宽带共集电极输出匹配电路.此输出匹配电路包含两个部分:一是带有两个电阻的射级分压器,并在与地相接的电阻上并联电容;二是在其输出端增加一段传输线和电容,构成低品质因素的宽带阻抗转换器.一般情况下,随着工作频率的升高,简单共集电极放大器的输出阻抗逐渐增大并呈现电感特性,该特性不易于输出匹配电路的设计.本文提出的RC补偿网络补偿了简单共集电极放大器输出阻抗的电感特性,使其在工作频带内近似为恒定值,从而在输出端获得了良好的宽带匹配.采用该宽带共集电极输出匹配电路作为输出级设计了一款宽带放大器,通过计算机仿真验证了其在带宽范围内具有良好的输出阻抗匹配特性.基于2μmInGaP/GaAs异质结双极型晶体管半导体工艺,该宽带放大器成功流片,通过测试验证了其在30kHz～23GHz频率范围内获得了良好的带宽增益和输出匹配,小信号增益S21保持在7.5dB以上,输出反射系数S22保持在-10dB以下.In modern wireless communication, high linear broadband amplifier is necessary and plays a critical role. The input and output return losses of the broadband amplifier typically vary with frequency, therefore, the construction of wide-band matching network is an essential issue in the design of broadband amplifier. Many publications have reported broadband amplifiers with various broadband matching design techniques such as negative-feedback technology, traveling wave technology and balance technology. In this paper, a novel broadband common-collector output buffer with resistance and capacitance （RC） compensation network is proposed to enhance the bandwidth of broadband amplifiers, especially to improve the broadband output matching. This circuit is composed of two parts. One is an emitter divider with two resistors, one resistor is connected to ground and paralleled with a capacitor. The other is a hybrid broadband impedance converter terminated at the emitter, consisting of a transmission line and a capacitor. In general, the output impedance of a conventional common collector buffer increases with frequency and it is of inductive character at some high frequencies. Therefore, it is very challenging to get a good broadband output matching in a wide frequency range. In this design, the output impedance equivalent circuit model of a conventional eommoweollector buffer is built, and the inductive character of the output impedance is compensated by using a RC compensation network. As a result, the output impedance becomes an approximately constant over the operating broadband frequency range, enables the buffer achieve a good broadband output matching at the output. The computer simulation results verify that this designed broadband common collector output buffer can achieve much better output matching than the conventional one. Implemented with 2 μm InGaP/GaAs heterojunction bipolar transistor technology, a broadband amplifier with this technique is designed and fabricated. It has a high gain-bandwidth produ

关 键 词：宽带共集电极放大器 电阻-电容补偿网络 输出匹配 

分 类 号：TN431.1[电子电信—微电子学与固体电子学]