Design and Analysis of a W-Band SiGe Direct-Detection-Based Passive Imaging Receiver

A W-band direct-detection-based receiver front-end for millimeter-wave passive imaging in a 0.18-μm BiCMOS process is presented. The proposed system is comprised of a direct-detection front-end architecture employing a balanced LNA with an embedded Dicke switch, power detector, and baseband circuitry. The use of a balanced LNA with an embedded Dicke switch minimizes front-end noise figure, resulting in a great imaging resolution. The receiver chip achieves a measured responsivity of 20-43 MV/W with a front-end 3-dB bandwidth of 26 GHz, while consuming 200 mW. The calculated NETD of the SiGe receiver chip is 0.4 K with a 30 ms integration time. This work demonstrates the possibility of silicon-based system-on-chip solutions as lower cost alternatives to compound semiconductor multi-chip imaging modules.