An Integrated Ka-Band Diplexer-Antenna Array Module Based on Gap Waveguide Technology With Simple Mechanical Assembly and No Electrical Contact Requirements

This paper presents the integration of a diplexer with a corporate feed network of a high gain slot array antenna at the Ka-band. A hybrid diplexer-splitter with a novel architecture is proposed to have compatibility for its direct integration with the feed network of the array antenna. A seventh-order hybrid diplexer-splitter is successfully integrated into a corporate feed network of a 16×16 slot array antenna. The proposed integrated diplexer-antenna module consists of three distinct metal layers without the need of electrical contacts between the different layers based on the recently introduced gap waveguide technology. The designed module has two channels of 650-MHz bandwidths each with center frequencies 28.21 and 29.21 GHz. The fabricated prototype provides good radiation and input impedance characteristics. The measured input reflection coefficients for both Tx/Rx ports are better than -13 dB with the measured antenna efficiency better than 60% in the designed passband, which includes the losses in the diplexer.