Patent ID: 6047601
Filing Date: 2000-04-11
Classification: G01N,H03H,Y10S

Abstract:
A system for removing a signal of predetermined frequency from a receive signal in a channel, comprising:a crystal notch filter circuit for filtering out a signal of predetermined frequency from an analog receive signal;a tuning circuit for tuning a resonant frequency of said crystal notch filter circuit, said tuning circuit having an input for receiving a tuning value and said resonant frequency being a function of said received tuning value; anda controller having a tuning mode for outputting a succession of tuning values to said input of said tuning circuit, detecting the respective amplitudes of the filtered analog receive signal or of signals derived from said filtered analog receive signals for each of said succession of tuning values, and determining a tuning value of said succession of tuning values which produces a minimum amplitude of said respective amplitudes, and having a data acquisition mode for outputting said determined tuning value to said tuning circuit.