Wideband inductorless minimal area RF front-end

Abstract

This paper presents the design of a fully integrated inductorless wideband RF front-end for wireless applications including WLAN, Bluetooth and UWB. The core of the circuit is comprised of a two stage LNA, followed by a standard Gilbert cell mixer and an output buffer for measurement purposes. The chip was fabricated in 65nm standard CMOS process. The RX offers an input matching of better than −10 dB in a bandwidth from 2.1 GHz to 8.2 GHz. To compensate the gain roll off the LNA incorporates an active inductor load, leading to a peak conversion gain of 20 dB at 3.5 GHz with a 3-dB bandwidth covering the whole matching frequency range. The minimal noise figure is 5.85 dB and kept below 7.5 dB within the whole matching and gain bandwidth. The linearity in terms of P1dB,out and oIP3 offers nearly constant behavior with −2 dBm and 7 dBm respectively. Excluding the buffer the circuit dissipates 47 mW. The die size of 370 µm by 570 µm is mainly dominated by the pad-frame, while the active area takes up only 0.05 mm2.