Title :
Second order /spl Delta//spl Sigma/ modulators using AlGaAs/GaAs HBTS
Author :
Nary, K.R. ; Beccue, S. ; Nubling, R. ; Pierson, R. ; Keh-Chung Wang ; Zampardi, P. ; Jayaraman, A.
Author_Institution :
Sci. Center, Rockwell Int. Corp., Thousand Oaks, CA, USA
Abstract :
We have successfully demonstrated one-bit, second-order delta-sigma modulators in a 50 GHz (F/sub t/) AlGaAs/GaAs heterojunction bipolar transistor process. The integrated modulator, consisting of a low-pass single bit modulator, clock generators and output buffers, has attained an SNR of 37 dB at a sample rate of 2 Gs/s for an oversampling ratio of 20. The circuit dissipates 1.92 W. To our knowledge, these are the first reported HBT delta sigma modulators.
Keywords :
III-V semiconductors; aluminium compounds; bipolar integrated circuits; gallium arsenide; heterojunction bipolar transistors; sigma-delta modulation; 1.92 W; 50 GHz; AlGaAs-GaAs; AlGaAs/GaAs HBTS; SNR; clock generators; heterojunction bipolar transistor; integrated modulator; low-pass single bit modulator; output buffers; oversampling ratio; second-order delta-sigma modulators; Circuits; Clocks; Delta modulation; Frequency; Gallium arsenide; Heterojunction bipolar transistors; Noise shaping; Pulse amplifiers; Quantization; Signal to noise ratio;
Conference_Titel :
Gallium Arsenide Integrated Circuit (GaAs IC) Symposium, 1994. Technical Digest 1994., 16th Annual
Conference_Location :
Phildelphia, PA, USA
Print_ISBN :
0-7803-1975-3
DOI :
10.1109/GAAS.1994.636974
