Development of RF CMOS receiver front-ends for ultrawideband

摘要

Ultra-Wideband (UWB) technology has become one of the hottest topics inwireless communications, for it provides cost-effective, power-efficient, high bandwidthsolution for relaying data in the immediate area (up to 10 meters). This workdemonstrates two different solutions for the RF front-end designs in the UWB receivers,one is distributed topology, and the other is based on traditional lumped elementtopology.The distributed amplifier is one of the attractive candidates for UWB Low NoiseAmplifier (LNA). The design, analysis and operation of the distributed amplifiers will bepresented. A distributed amplifier is designed with Coplanar Waveguide (CPW)transmission lines in 0.25-?m CMOS process for time domain UWB applications. Newdesign techniques and new topologies are developed to enhance the power-efficiencyand reduce the chip area. A compact and high performance distributed amplifier withPatterned Grounded Shield (PGS) inductors is developed in 0.25-?m CMOS process.The amplifier has a measurement result of 7.2dB gain, 4.2-6dB noise figure, and less than -10dB return loss through 0-11GHz. A new distributed amplifier implementingcascade common source gain cells is presented in 0.18-?m CMOS. The new amplifierdemonstrates a high gain of 16dB at a power consumption of 100mW, and a gain of10dB at a low power consumption of 19mW.A UWB LNA utilizing resistive shunt feedback technique is reported in 0.18-?mCMOS process. The measurement results of the UWB LNA demonstrate a maximumgain of 10.5dB and a noise figure of 3.3-4.5dB from 3-9.5GHz, while only consuming9mW power.Based on the distributed amplifier and resistive shunt-feedback amplifier designs,two UWB RF front-ends are developed. One is a distributed LNA-Mixer. Unlike theconventional distributed mixer, which can only deliver low gain and high noise figure,the proposed distributed LNA-Mixer demonstrates 12-14dB gain ,4-5dB noise figureand higher than 10dB return loss at RF and LO ports over 2-16GHz. To overcome thepower consumption and chip area problems encountered in distributed circuits, anotherUWB RF front-end is also designed with lumped elements. This front-end, employingresistive shunt-feedback technique into its LNA design, can achieve a gain of 12dB andnoise figure of 8-10dB through 3-10GHz, the return loss of less than -10dB from 3-10GHz at RF port, and less than -7dB at LO port, while only consuming 25mA currentfrom 1.8V voltage supply.