DESIGN of a 3-DB directional coupler based on groove gap waveguide technology

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.