Array of 296-GHz CMOS Concurrent Transceiver Pixels With Phase and Amplitude Extraction Circuits for Improving Reflection-Mode Imaging Resolution

Abstract

A 1 × 3 array of 296-GHz complementary metal oxide semiconductor concurrent transceiver pixels incorporating a low noise amplifier, a differential gain stage, and a double-balanced I/Q mixer and a quadrature local oscillator generator for extraction of baseband signal amplitude and phase in addition to the RF section in an area of ∼ (λ/2) ² is demonstrated. The effective isotropic radiated power of the array is ∼−6 dBm and the minimum double sideband receiver pixel noise figure is ∼48 dB. An E-shaped patch antenna is used to broaden the antenna bandwidth (14-GHz -10-dB |S ₁₁ | bandwidth). Using a pair of these arrays, lens-less short-range reflection mode imaging of a target ∼1 cm away through a cardboard covering is demonstrated. The phase and amplitude outputs enable a synthetic increase of the effective aperture to the scan area from the pixel area for improved image quality and resolution. The use of phase combining for the 1 × 3 transmitter array also improves the isolation between the pair for reflection-mode imaging which limits the stand-off range by ∼10 dB (to ∼70 dB) compared to that when a pair of single pixels with a conductive wall is used.