Wideband aperture coupled substrate integrated waveguide power divider based on half mode analysis

Abstract

A wideband substrate integrated waveguide (SIW) power divider based on half mode analysis is presented in this article. The structure is constructed by two substrate layers and three metal layers. Two symmetrical longitudinal apertures etched on the middle ground are introduced to realize the equal power division, and couple the signal from the SIW to the upper layer output ports simultaneously. Two fork-type microstrip lines on the top metal layer are used to improve the bandwidth of the power divider. The equivalent circuit based on the half mode analysis method is presented for theoretical analysis and further design of the power divider, and good impedance matching can be obtained accordingly. For demonstration, a power divider prototype with the dimension of 48 × 73 × 1.38 mm3 is designed, fabricated, and measured. Good agreement is observed between the simulated and measured results. The measured return loss of the SIW power divider is better than 12 dB in the frequency range of 6.2 ~ 10.3 GHz, and the insertion loss is around 1.6 dB over the entire frequencies of interest.