Title :
Basic principles and new solutions for analog sampled-data image rejection mixers
Author :
Pun, Kong-Pang ; Franca, José E. ; Leme, C. Azeredo
Author_Institution :
Inst. Superior Tecnico, Lisbon, Portugal
Abstract :
This paper briefly reviews basic principles of image rejection (IR) receivers, and then proposes a new architecture which is suitable for CMOS technology. The critical issue in the IR receiver is the phase accuracy and magnitude balance of the 90° phase shifting network. The proposed IR receiver employs a 3rd order IIR switched-capacitor (SC) quasi-Hilbert filter to act as a broad band 90° phase shifter. This SC phase shifter generates only 0.1° phase error and has a capacitor-ratio insensitive magnitude response. The simulated overall image rejection ratio is over 40 dB in a bandwidth equal to 25% of the sampling frequency of the SC circuit
Keywords :
CMOS analogue integrated circuits; Hilbert transforms; IIR filters; UHF integrated circuits; UHF mixers; UHF phase shifters; analogue processing circuits; cordless telephone systems; radio receivers; sampled data circuits; switched capacitor filters; 90° phase shifting network; CMOS technology; SC circuit sampling frequency; analog sampled-data image rejection mixers; architecture; broad band 90° phase shifter; capacitor-ratio insensitive magnitude response; cordless phone receiver; magnitude balance; phase accuracy; third-order IIR switched-capacitor quasi-Hilbert filter; Bandwidth; CMOS technology; Chromium; Energy consumption; Paper technology; Passive filters; Phase shifters; RF signals; Radio frequency; Receivers;
Conference_Titel :
Electronics, Circuits and Systems, 1998 IEEE International Conference on
Conference_Location :
Lisboa
Print_ISBN :
0-7803-5008-1
DOI :
10.1109/ICECS.1998.813959
