An interference robust 0.18μm CMOS 3.1-8GHz receiver front-end for UWB radio

This paper addresses the problem of 5-6GHz WLAN interferer rejection in a receiver front-end, operating from 3.1 GHz to 8 GHz, for multiband OFDM ultra-wide-band applications. The direct conversion IC, realized in a 0.18μm CMOS technology, comprises a multiresonance single-ended LNA, a single-balanced mixer and a second order low pass filter. Fabricated dies have been bonded on PCB for characterization. The front-end, drawing 10mA from 1.8V, achieves the following performances: when signals belong to group 1, 5.2dB and 7.3dB minimum and maximum NF respectively, a 1dB gain desensitization with -6dBm interferer at 5.5GHz, minimum IIP3 = -3.5dBm and minimum IIP2 = +34.5dBm. When signals belong to group 3: 5.3dB and 7.7dB minimum and maximum NF respectively, a 1dB gain desensitization with -6.5dBm interferer at 5.5GHz, minimum IIP3 = -3.15dBm and IIP2 = +35.2dBm.