Title :
An inductorless active notch filter for RF image rejection
Author :
Chang, Yuyu ; Choma, John, Jr. ; Wills, Jack
Author_Institution :
Univ. of Southern California, Los Angeles, CA, USA
Abstract :
A CMOS inductorless active notch filter is discussed and designed with the emphasis on low-noise, low-power, and gigahertz-range circuits suitable for portable wireless equipment. The proposed filter utilizes two Q-enhancement techniques to circumvent the low Q characteristics inherent in the simple feedback circuit. The frequency tuning is almost independent of Q tuning, facilitating the design of the automatic tuning circuitry. The stability of the filter is also further discussed. Simulations using 0.5 μm CMOS technology demonstrate the feasibility of the tunable notch filter for DECT wireless applications. Simulation results show 4.17 dB voltage gain and 69 dB input dynamic range at a passband centered at 1900 MHz. The image signal suppression is 70 dB at 1482 MHz and the power consumption is 34 mW
Keywords :
CMOS analogue integrated circuits; Q-factor; UHF filters; UHF integrated circuits; active filters; circuit stability; circuit tuning; cordless telephone systems; notch filters; 0.5 micron; 1900 MHz; 34 mW; 4.17 dB; CMOS inductorless active notch filter; DECT portable wireless equipment; Q-factor; RF image rejection; frequency tuning; stability; Active filters; CMOS technology; Circuit optimization; Circuit simulation; Circuit stability; Feedback circuits; Gain; Radio frequency; Tunable circuits and devices; Voltage;
Conference_Titel :
Circuits and Systems, 1999. 42nd Midwest Symposium on
Conference_Location :
Las Cruces, NM
Print_ISBN :
0-7803-5491-5
DOI :
10.1109/MWSCAS.1999.867234
