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Design of terahertz frequency scanning reflector antenna and its application in direction‐of‐arrival estimation

A novel frequency scanning-based direction-of-arrival (DOA) estimation scheme is proposed at terahertz (THz) band. The diffraction enhancement mechanism, focusing the superposition of the diffracted beam radiated from each element in one unit cell, is expanded to the 0.3 THz band. The frequency scanning reflector antenna (FSRA) operating at 235–330 GHz is proposed with high diffraction efficiency. Angular super-resolution algorithm is proposed based on the FSRA. Maximum likelihood (ML) method, traditionally used in array signal processing, is extended to the novel frequency scanning system based on the FSRA. The model of FSRA manifold vector is constructed. A FSRA operating on 0.3 THz frequency band was experimented, based on which the DOA estimation system is constructed. The resolution of the frequency scanning ML algorithm can be obtained on the level of half of the 3 dB beamwidth by the proof-of-principle experiments in 0.3 THz band.