Quadrature Harmonic Self-Oscillating Mixer: Toward Large Array Multifunction Receiver Systems

In this article, a quadrature harmonic self-oscillating mixer (QHSOM) is proposed, studied, and demonstrated for future large array multifunction receivers. Its implementation is based on single-stage direct-conversion harmonic receiver topology. The proposed receiver unit is composed of a pair of harmonic self-oscillating mixers (HSOMs), which are injection-locked through their second oscillation harmonic to generate quadrature phase oscillation and isolate oscillation tanks and suppress crosstalk between quadrature channels. To our best knowledge, the proposed receiver configuration is the most compact standalone quadrature receiver topology realization ever reported so far. Its structural simplicity, in addition to enhanced receiving performance, makes it scalable to millimeter-wave (mmW) large array receiver realizations. Besides, substantiated capabilities of communication and radar/sensing accompanied by operation status flexibility within an array make it an appealing candidate for integrated multifunction systems. Transmission and demodulation of digital modulated signals (M-QAM) at third-harmonic mixing is successfully demonstrated for the proof-of-concept (PoC). Simulation and measurement results are set to confirm the feasibility and viability of the proposed quadrature receiver.