A dual-mode 80 MHz bandpass /spl Delta//spl Sigma/ modulator for a GSM/WCDMA IF-receiver

The authors present a band-pass modulator operating at 80 MHz which combines frequency down-conversion with A/D conversion. The two SC resonators are implemented using a single opamp. A single-bit quantizer and feedback is used for GSM, but 4 b quantizer is used for WCDMA. Measured peak SNRs are 80 dB for 270 kHz B/W (GSM), and 48 dB for 3.84 MHz B/W (WCDMA).

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