An Ultra Wideband (UWB) Mixer with 0.18UM RF CMOS Technology

Abstract

In this paper a CMOS down-conversion mixer for UWB applications is presented. The mixer circuit, designed using a standard 0.18mum RF CMOS technology, is an integral part of an entire UWB transceiver chip, working at the 3.1-10.6 GHz frequency range. The core of the mixer has been designed based on Gilbert cell architecture and uses a current injection method for increasing the linearity. For matching of RF and LO inputs to 50Omega a wideband matching circuit, using passive on-chip components, has been designed which provides a good match over the entire frequency range. A simple buffer is incorporated at the IF output. The simulated conversion gain of the mixer is greater than 10dB. The 1dB compression point, referred to input, is -10dBm and the IIP3 point is 4dBm. The RF return-loss is well below -10dB. Also, the LO-IF isolation is greater than -30dB, while the NF is about 10dB. The DC power consumption of the mixer is only 10mW. All characteristics are achieved for the entire frequency range of 3.1-10.6 GHz and meet the UWB standard requirements. In the paper it is shown that this mixer, which uses only a 1.8V supply, has considerable advantages over previously published mixers designed for this purpose