Compact power divider based on half mode substrate integrated waveguide (HMSIW) with arbitrary power dividing ratio

Abstract

Design and realisation of a compact power divider based on half mode substrate integrated waveguide (HMSIW) with an arbitrary power dividing ratio is presented. This design consists of a substrate integrated waveguide (SIW) transition, two bisected HMSIW transitions by a gap, an SIW-to-microstrip transition, and two microstrip feed lines. In addition, a resistor is attached between two HMSIW transitions. To adjust the power division ratio, four parameters are introduced. Furthermore, four graphs are plotted using a three-dimensional electronmagnetic (3D EM) simulator to graphically determine the introduced parameters. In this study, three circuits with power division ratios of 1:1, 1:4, and 1:8 are simulated using the 3D EM simulator and fabricated on a Rogers RO4003C substrate. The results show a good agreement between the simulated and measured results. The measured results display these circuits (1:1, 1:4, and 1:8) have the bandwidths of 70, 36, and 40%, respectively. Moreover, the proposed structures (1:1, 1:4, and 1:8) are compact and their overall sizes are$1.13 \times 1.04\lambda _g^2 $,$0.96 \times 0.91\lambda _g^2 $, and$0.81 \times 0.78\lambda _g^2 $, respectively. These structures have the advantages of the compactness in size, wide bandwidth, high power division ratio (from 1:1 to 1:16), and compatibility with planar circuits.