Title :
A 6th-order continuous-time bandpass /spl Sigma//spl Delta/ modulator for digital radio IF
Author :
van Engalen, J. ; van de Plassche, R. ; Sokvoort, E. ; Venes, A.
Author_Institution :
Eindhoven Univ. of Technol., Netherlands
Abstract :
A bandpass SD Modulator (SDM) ADC uses negative feedback of a bandpass-filtered error-signal and a high oversampling ratio to reduce the in-band errors of a low-resolution quantizer. As high-order (>4) bandpass SDMs exhibit signal-dependent stability, multibit quantizers are often used to lower the quantization noise of a 2nd or 4th order SDM. However, the accuracy required of the intermediate quantizer levels is high as mismatch affects the overall SDM performance. A 6th-order SDM has a single-bit quantizer for digitizing IF signals of 10.7 MHz.
Keywords :
circuit feedback; continuous time systems; digital radio; quantisation (signal); sigma-delta modulation; 10.7 MHz; IF signals; bandpass-filtered error-signal; continuous-time bandpass /spl Sigma//spl Delta/ modulator; digital radio IF; in-band errors; intermediate quantizer levels; low-resolution quantizer; mismatch; multibit quantizers; negative feedback; oversampling ratio; quantization noise; signal-dependent stability; Circuits; Delta modulation; Digital communication; Digital modulation; Frequency; Q factor; Quantization; Resonator filters; Stability; Voltage;
Conference_Titel :
Solid-State Circuits Conference, 1999. Digest of Technical Papers. ISSCC. 1999 IEEE International
Conference_Location :
San Francisco, CA
Print_ISBN :
0-7803-5126-6
DOI :
10.1109/ISSCC.1999.759093
