Harmonic Interferometric Receiver for Multifunction Wireless Systems

In next-generation wireless systems, harmonic diversity-across both sensing and communication functionalities-promises to redefine the design paradigm of RF receivers. This work proposes a four-port quad-band harmonic-responsive linear interferometric receiver capable of simultaneously performing multiband integrated sensing and communication (ISAC). The architecture leverages a hybrid multiplexing scheme up to the seventh odd harmonic of the design frequency to perform concurrent RF functionalities. Based upon a comprehensive theoretical framework, a proofof-concept receiver is designed and fabricated to validate the architecture. Successful demodulation of up-to 128-QAM signals alongside multiband frequency-modulated continuous wave (FMCW) chirps, with desired performances at 2. 75, 8.25, 13.75 and 19.25 GHz, demonstrate the feasibility and effectiveness of the approach. To the best of the author's knowledge, this is the very first up-to-the-seventh-harmonic multiband interferometric receiver that supports distinct RF functions simultaneously using a single, reusable circuit. Such harmonic expansion of the effective bandwidth of linear interferometric receivers is believed to have great potential in establishing of next-generation harmonically diverse wireless systems.