426-GHz Concurrent Transceiver Pixel in 65-nm CMOS for Active Imaging

This article demonstrates a 426-GHz concurrent transceiver imaging pixel in 65-nm CMOS that can be scaled to form a two-dimensional focal plane array. The pixel integrates a transmitter, a coherent receiver using a star-type triple-push oscillator, and an on-chip patch antenna into an area of 380×470 μm². The pixel achieves a sensitivity of −89.6 dBm for a 1-kHz bandwidth with the third order subharmonic self-oscillating mixing in RX mode. This sensitivity is the lowest for imagers operating above 300 GHz. In TX mode, the pixel radiates −17.9 dBm. The pixel consumes 52 mW of dc power. If a 6-cm diameter Cassegrain reflector with a simulated gain of 47-dB gain is used, a link margin of 5.3 dB is expected for reflection-mode imaging of an object with a radar cross-section of ∼0.6 cm² at a range of 1 m.