METHOD AND APPARATUS FOR OPTIMIZING DYNAMIC RANGE OF A WIDEBAND ANALOG-TO-DIGITAL CONVERTER

摘要

A direct down conversion receiver 100 includes a signal filter 105 having a selectable frequency response for receiving an input signal 102. The filtered signal is amplified by a variable gain amplifier 112, and the amplified signal is received as input by an analog-to-digital converter 114. The analog-to-digital converter generates a series of digital samples representative of the filtered signal. A controller 116 measures a corresponding peaking ratio of the filtered signal from the series of digital samples for each of a plurality of frequency bands and selects the frequency response of the signal filter as a function of the measured peaking ratios. The signal filter may include an adjustable highpass filter 108 and an adjustable lowpass filter 106. The cutoff frequency of the lowpass filter and the cutoff frequency of the highpass filter are selected to attenuate the level of the input signal in one or more of the plurality of frequency bands so that the signal presented to the analog-to-digital converter has a peaking ratio approximately equal to a selected peaking ratio threshold across the frequency range of the input signal.