Ultra-compact millimeter-wave substrate integrated waveguide crossover structure utilizing simultaneous electric and magnetic coupling

An ultra-compact wideband crossover is proposed and realized by using vertical coupling of both electric and magnetic fields simultaneously. The four-port multilayered substrate integrated waveguide (SIW) crossover structure consists of two different types of 90° hybrid coupler integrated at the same physical location. The magnetic field (H) is coupled through slots etched adjacent to the side walls of waveguide and the electric field (E) is coupled through slots etched on the middle of waveguide. Measured insertion loss is less than 0.9 dB over an operating bandwidth of 16.6% at 35 GHz. The experimental prototype occupies a compact size of 4.8γg×3.7γg×0.145γg including its input transitions.