In this letter, a groove gap waveguide (GGW) based 3‐dB directional coupler is proposed. The designed component is composed of three parts: GGW structure, extra matching pins and GGW to standard SMA transition. The designed quadrature 3‐dB coupler is optimized to work in the Ku‐band covering 13–15 GHz. Measured results show that over 14.3% bandwidth, 20 dB isolation and 1.2 VSWR is achieved. The main advantage of GGW‐based components is that it does not require good electrical contact among different metallic parts of the structure which considerably simplifies the manufacturing processes and hence reduces cost especially for millimeter‐waves applications.

A groove gap waveguide diplexer is presented for Ku‐band applications. The manifest advantage of using this technology is its ability to remove requirement of electrical contact between the different layers of the structure. The proposed diplexer is composed of coupled gap waveguide resonators without additional waveguide elements. A prototype is fabricated and measured for experimental verification. The return losses of the channel filters of diplexer are higher than about 20 dB, in the desired frequency bands centered 14 and 15.5 GHz. A high degree of agreement between the measurements and simulations has been found.