Substrate-Integrated Waveguide Power Combiner/Divider Incorporating Absorbing Material

In this letter, substrate-integrated waveguide (SIW) power combiner/divider incorporating absorbing material for isolation is presented. Based on the Riblet coupler theory, the proposed SIW power combiner/divider contains two extra ports to improve isolation between the dividing ports. Its longitudinal axis symmetry illustrates its equal power-dividing property, and ensuring the dividing ports to have good and balanced amplitude and phase properties. By loading the isolated ports with shaped absorbing material, an SIW power combiner/divider prototype is realized. Measured results are in good agreement with simulated ones, and a fractional bandwidth of 36% with over 15-dB isolation is achieved, which is wider than other similar SIW power dividers.