RECEIVER IF SYSTEM WITH ACTIVE FILTERS

摘要

A high dynamic range receiver IF system using limited dynamic range IF filters is disclosed. A variable gain amplifier amplifies a first IF signal. The amplified first IF signal is then applied to an image suppression mixer for suppressing an image component of the amplified first IF signal to provide adequate image suppression for a radio system, wherein the image suppression mixer outputting an image suppressed second IF signal. An active bandpass filter then filters the unwanted components from the second IF signal. The filtered signal is then hard limited in a limiting amplifier which outputs a limited IF signal. A logarithmic detector then provides a received signal strength indicator.