Development of RF CMOS receiver front-ends for ultra-wideband communications

Ultra-Wideband (UWB) technology has become one of the hottest topics in wireless communications, for it provides cost-effective, power-efficient, high bandwidth solution for relaying data in the immediate area (up to 10 meters). This work demonstrates 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 element topology.;The distributed amplifier is one of the attractive candidates for UWB Low Noise Amplifier (LNA). The design, analysis and operation of the distributed amplifiers will be presented. A distributed amplifier is designed with Coplanar Waveguide (CPW) transmission lines in 0.25-mum CMOS process for time domain UWB applications. New design techniques and new topologies are developed to enhance the power-efficiency and reduce the chip area. A compact and high performance distributed amplifier with Patterned Grounded Shield (PGS) inductors is developed in 0.25-mum 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 implementing cascade common source gain cells is presented in 0.18-mum CMOS. The new amplifier demonstrates a high gain of 16dB at a power consumption of 100mW, and a gain of 10dB at a low power consumption of 19mW.;A UWB LNA utilizing resistive shunt feedback technique is reported in 0.18-mum CMOS process. The measurement results of the UWB LNA demonstrate a maximum gain of 10.5dB and a noise figure of 3.3-4.5dB from 3-9.5GHz, while only consuming 9mW 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 the conventional distributed mixer, which can only deliver low gain and high noise figure, the proposed distributed LNA-Mixer demonstrates 12-14dB gain, 4-5dB noise figure and higher than 10dB return loss at RF and LO ports over 2-16GHz. To overcome the power consumption and chip area problems encountered in distributed circuits, another UWB RF front-end is also designed with lumped elements. This front-end, employing resistive shunt-feedback technique into its LNA design, can achieve a gain of 12dB and noise 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 current from 1.8V voltage supply.