A BiCMOS Ultra-Wideband 3.1–10.6-GHz Front-End

Abstract

This paper presents a direct-conversion receiver for FCC-compliant ultra-wideband (UWB) Gaussian-shaped pulses that are transmitted in one of fourteen 500-MHz-wide channels within the 3.1–10.6-GHz band. The receiver is fabricated in 0.18- m SiGe BiCMOS. The packaged chip consists of an un- matched wideband low-noise amplifier (LNA), filter, phase-splitter, 5-GHz ISM band switchable notch filter, 3.1–10.6-GHz local os- cillator (LO) amplifiers, mixers, and baseband channel-select filters/buffers. The required quadrature single-ended LO signals are generated externally. The average conversion gain and input /49/100/66are 32 dB and 41 dBm, respectively. The unmatched LNA provides a system noise figure of 3.3 to 5 dB over the entire band. The chip draws 30 mA from 1.8 V. To verify the unmatched LNA’s performance in a complete system, wireless testing of the front-end embedded in a full receiver at 100 Mbps reveals a /49/48 /51bit-error rate (BER) at 80 dBm sensitivity. The notch filter suppresses out-of-band interferers and reduces the effects of intermodulation products that appear in the baseband. BER improvements of an order of magnitude and greater are demonstrated with the filter.