Title :
An adaptive offset cancellation mixer for direct conversion receivers in 2.4 GHz CMOS
Author :
Lehne, M. ; Stonick, J.T. ; Moon, U.
Author_Institution :
Dept. of Electr. & Comput. Eng., Oregon State Univ., Corvallis, OR, USA
Abstract :
In this paper we present a new circuit design for a 2.4 GHz CMOS direct conversion mixer incorporating adaptive offset cancellation. The basic circuit structure is that of a Gilbert cell mixer. Offsets are cancelled by dynamically varying the bias on the loads, which are designed to provide constant impedance independent of the load cancellation current. The bias control is regulated via an adaptive dual-loop (gear-shifting) algorithm. Performance is good when canceling offsets of any realistic magnitude. The mixer has a gain of 6.4 dB, IIP3 of 17 dBm and noise figure of 17 dB
Keywords :
CMOS analogue integrated circuits; UHF integrated circuits; UHF mixers; adaptive signal processing; low-power electronics; radio receivers; 17 dB; 2.4 GHz; 6.4 dB; CMOS; Gilbert cell mixer; IIP3; adaptive dual-loop algorithm; adaptive offset cancellation mixer; bias control; circuit design; constant impedance; direct conversion receivers; gear-shifting algorithm; load cancellation current; Circuit synthesis; Image converters; Impedance; Low pass filters; Moon; Noise cancellation; RF signals; Radio frequency; Reflector antennas; Transceivers;
Conference_Titel :
Circuits and Systems, 2000. Proceedings. ISCAS 2000 Geneva. The 2000 IEEE International Symposium on
Conference_Location :
Geneva
Print_ISBN :
0-7803-5482-6
DOI :
10.1109/ISCAS.2000.857094
