一种高性能宽带直接变频射频前端设计

A High Performance Broadband Direct Conversion Front-End

提出一种宽带(250MHz^4.7GHz)无电感BiCMOS射频前端结构,包含低噪声跨导放大器(LNTA)、带电阻无源混频器和跨阻级。低噪声跨导放大器使用了噪声和线性度消除技术,例如输入交叉耦合结构、互补输入和电流复用技术。带电阻无源混频器采用退化电阻来提高线性度。仿真结果表明,当电源电压为3.3V时,总电流为9.38mA,噪声系数为9.8dB(SSB),电压转换增益为20dB,输入3阶交调为+11.8dBm。

A broadband （250 MHz^4.7 GHz） inductorless BiCMOS front-end with a low noise transconductance amplifier （LNTA）, a resistively degenerated passive mixer and a transimpedance stage were presented. The LNTA utilized noise and distortion cancellation, such as input cross-coupling and current reuse complementary input. A resistively degenerated passive mixer was used to improve the linearity （IIP2 and IIP3）. The simulated results showed 9.8 dB single-sideband （SSB） NF, 20 dB voltage conversion gain, ＋ 11.8 dBm IIP3, while consuming 9.38 mA from 3.3 V supply.