Receiver with sigma-delta analog-to-digital converter for sampling a received signal

Abstract

A receiver comprising a sigma-delta analog-to-digital converter (.SIGMA..DELTA. ADC) can be utilized in one of four configurations, as a subsampling bandpass receiver, a subsampling baseband receiver, a Nyquist sampling bandpass receiver, or a Nyquist sampling baseband receiver. For subsampling .SIGMA..DELTA. receivers, the sampling frequency is less than twice the center frequency of the input signal into the .SIGMA..DELTA. ADC. For Nyquist sampling .SIGMA..DELTA. receivers, the sampling frequency is at least twice the highest frequency of the input signal into the .SIGMA..DELTA. ADC. For baseband .SIGMA..DELTA. receivers, the center frequency of the output signal from the .SIGMA..DELTA. ADC is approximately zero or DC. For bandpass .SIGMA..DELTA. receivers, the center frequency of the output signal from the .SIGMA..DELTA. ADC is greater than zero. The sampling frequency can be selected based on the bandwidth of the input signal to simplify the design of the digital circuits used to process the output samples from the .SIGMA..DELTA. ADC. Furthermore, the center frequency of the input signal can be selected based on the sampling frequency and the bandwidth of the input signal. The .SIGMA..DELTA. ADC within the receiver provides many benefits.

Dependencies are inferred from the claim text.