A Compact Stacked SIW Six-Port Junction

This letter presents a compact substrate-integrated waveguide (SIW) six-port junction. It consists of two
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-plane power dividers, two cruciform quadrature hybrid couplers, and one self-compensating quadrature phase shifter. In contrast to state-of-the-art implementations, the couplers are positioned on top of each other, which, in total, reduces the overall occupied area by 40%. The six-port junction is fabricated and measurements confirm its functionality in the frequency range between 22 and 28 GHz.