Ku-band Two-Section Branch-Line Coupler Based on Ridge Gap Waveguide Technology

In this paper a Ku-band two-section 3-dB branch-line coupler based on ridge gap waveguide technology is proposed and simulated. This structure has the advantages of branch-line coupler that compensates some defects in planar technologies such as microstrip and SIW in high frequency and high power applications. Also, it has the advantages of the novel RGW technology, such as broad bandwidth, low loss, low sensitivity to fabrication error, easy integration of active components, usable at high frequencies, etc. Thus, using RGW technology and branch-line type building-block for implementation foundation makes it proper to high-power low-cost millimeter-wave applications. In this paper a two-section Ku-band branch-line coupler is designed and simulated that can be used in an arbitrary 1:2^N power divider/combiners. Besides, RGW-to-SMA and RGW-to-WR62 transitions are designed and simulated. The simulation results show that return loss and insertion loss are -10dB and-3 dB respectively. Also the achieved bandwidth is more than 25%. (Designs are simulated using both CST Microwave Studio and HFSS soft wares).