A high dynamic range multi-standard CMOS mixer for GSM, UMTS and IEEE802.11b-g-a applications

Abstract

Software defined radios are a topic of intense research and constitute one key industry need for future generation wireless products. In this paper, we investigate the down-conversion mixer, a particularly challenging block, due to the stringent dynamic range requirements set by cellphone applications and the wide operation bandwidth. The proposed mixer is based on a Gilbert cell and operates between 900 MHz and 6 GHz. The parasitic capacitor of the switching pair, main responsible for the limited dynamic range, is tuned out by means of a spiral inductor at 900 MHz, a transformer based programmable inductor between 1.7 GHz and 2.4 GHz, and a small spiral in the 5 GHz-6 GHz range. Prototypes have been integrated in a 65 nm CMOS technology and are operated from a 1.2 V supply. Minimum IIP2 and maximum average noise are 65 dBm and 5.4 nV/sqrt (Hz) in DCS. The mixer current consumption is 7.5 mA.