A 0.5-8GHz Reconfigurable CMOS RF Receiver Front-End for CR and DPA Applications

This brief presents a 0.5-8 GHz CMOS RF receiver front-end (RxFE) tailored for cognitive radio (CR) and digital phased array (DPA) applications. The RxFE comprises a wideband mixer with noise suppression capability, along with a reconfigurable band-pass filter (BPF) designed to adapt to different intermediate frequencies (IFs) and signal bandwidths (SBWs). Additionally, the BPF functions as a programmable gain amplifier (PGA), enabling support for a large dynamic range with fine gain adjustment. The BPF offers a programmable center frequency (CF) range from 250 MHz to 450 MHz with a 5 MHz step, as well as support for tunable passbands from 60 MHz to 240 MHz with 5 MHz resolution. The RF RxFE provides a gain control range of 15-to-55 dB with a 0.5 dB gain step. Fabricated in a standard 55 nm CMOS process, the prototype occupies an area of $2.29~mm^{2}$ including pads, consuming 75.6mW power without an on-chip high-IF BPF and 226.8mW with it at 2.3GHz LO input. Measurement results indicate that the prototype achieves approximately 10 ns gain switching time and 350 ns frequency hopping time when driven by an external fast-switching local oscillation (LO) signal, attributed to its high IF architecture. The receiver demonstrates exceptional agility, meeting the stringent requirements of CR and DPA applications.