Design of a dual-frequency microstrip planar array antenna operating in the Ka-band

This study proposes a novel Ka-band microstrip planar array antenna featuring dual-band operation. By implementing a one-to-eight T-junction power divider, efficient excitation of array elements is achieved with impedance matching. Furthermore, the incorporated decoupling structure (DS) effectively suppresses mutual coupling between antenna elements, mitigating mutual coupling effects and optimizing radiation performance. The proposed antenna operates across dual frequency bands (34-35 GHz and 35-36 GHz), exhibiting inter-element isolation below −35 dB, average gain exceeding 13.5 dBi, and H-plane half-power beamwidths narrower than 20°. Characterized by stable bandwidth, low mutual coupling, high gain, and directional radiation patterns, this antenna demonstrates promising applications in millimeter-wave communications, radar systems, satellite remote sensing.