晶体管混频器混频增益的简化计算

本文介绍一种方法简单、便于学生理解的分析晶体管混频器混频增益的简化计算方法.该方法从晶体管的电流方程入手,通过分析晶体管混频器的混频原理,得到了输出中频电流和混频跨导、混频增益的简明数学表示.通过对典型混频器电路的仿真,验证了该方法的有效性.该方法与传统的时变偏置电压分析方法相比,混频跨导和混频增益容易求得,解决了以往混频跨导基本是一个概念参数而难以确定具体数值的问题.

Predigested Calculating of Transistor Mixer Conversion Gain

This paper introduces a predigested calculate method to analyze the transistor mixer conversion gain, which is simple and comprehensible. Start with the electric current equation of transistor, and by the analysis of mixer theories of transistor mixer, this method obtains the compendious mathematical expres- sion of output medium frequency current and mixer transconductance . The method is validated by the emulation of typical mixer circuits. Compared with the traditional method of time-varying offset voltage, this method could get the mixer transconductance and conversion gain swing more easily, and overcome the former questions that the mixer transconductance is basically a conceptional parameter which is hard to be confirm its material numerical value.