Design of low profile wideband high power waveguide to substrate integrated waveguide coupler.

This paper presents a new wideband waveguide substrate integrated waveguide (SIW) coupler with maximum deviation of ±0.5 dB in a 7.5–12.25 GHz bandwidth (48% fractional bandwidth). Proposed coupler consists of the standard WR90 waveguide and single layer/double clad SIW printed circuit board (PCB) which is placed crosswise on the waveguide. Proposed three port coupler (isolated port was ended with match load) has a two coupling level (average of coupling in 8–12 GHz frequency range) of 43.2 and 58.3 dB, which is correspond with the hole diameter of 3.5 and 3 mm, respectively. The main contribution of this work is based on the hybrid techniques of SIW and RWG for coupler design in the high power microwave application. Validation of the simulation results with measurement one proves that the proposed X‐band waveguide to SIW coupler is a good candidate for use in high power industrial/commercial applications. [ABSTRACT FROM AUTHOR]