基于超外差接收的宽带混频小信号放大器设计

Design of Broadband Frequency Small Signal Amplifier Based on Superheterodyne Receiver

宽带混频小信号放大器是通过混频放大实现对微弱信号有效放大接收的装置,混频小信号放大器受到自激寄生振荡的影响,信号接收失真较大。提出一种基于超外差接收的受自激振荡的宽带混频小信号放大器电路设计方法。设计自激寄生振荡接收机前置电路,根据不同的接收信号强度,选择最佳的增益,得到自激寄生振荡可变增益控制放大器电路,采用输入控制模块和节电控制模块组合设计,实现自激振荡的宽带混频小信号放大器改进。仿真结果表明,采用该电路设计方法能有效实现对宽带混频的小信号放大滤波,干扰较少,提高了信号的检测性能。

Broadband mixing small signal amplifier is amplified by mixing receiving device effective amplification of weak signal, frequency small signal amplifier is affected by self parasitic oscillation, signal distortion. Put forward a kind of broad-band by mixing small signal amplifier circuit design method of self oscillation of superheterodyne receiver based on. Design of self parasitic oscillation receiver front-end circuit, according to the received signal strength of different, choose the best gain, get self parasitic oscillation in variable gain control amplifier circuit, the input control module, control module and power saving design, the realization of broadband mixing small signal amplifier self-excited oscillation improvement. The simulation results show that, the design method of the circuit can effectively achieve the small signal amplification and fil-tering of broadband mixer, less interference, improving the signal detection performance.