Patent ID: 7843257

Claim:
A bandpass filter calibration apparatus comprising: a MUX having a plurality of inputs, an output and a control input; a first signal source of a frequency f 0 coupled to a first input of said MUX; a second signal source of a frequency f 1 coupled to a second input of said MUX; a bandpass filter having an input coupled to said output of said MUX, an output and a control input; a rectification circuit having an input coupled to an output of said bandpass filter, said rectification circuit comprising a plurality of rectifiers having a corresponding plurality of rectifier outputs; a summer having a plurality of inputs coupled to said plurality of rectifier outputs; a low pass filter having an input coupled to an output of said summer; an ADC having an input coupled to an output of said low pass filter; and a calibration processor unit having an input coupled to an output of said ADC, said calibration processor unit having a MUX control output coupled to said control input of said MUX and a filter control output coupled to said control input of said bandpass filter, wherein said calibration processor unit controls said MUX to selectively apply said first signal source and said second signal source to said bandpass filter and calibrates said bandpass filter by a least one of increasing filter center frequency and decreasing filter center frequency.