Power Divider/Combiner using Half-Mode Substrate Integrated Waveguide (HMSIW) Technology with High Power and High Isolation

Abstract

ABSTRACT A power divider/combiner using half-mode substrate integrated waveguide (HMSIW) and microstrip transmission lines with high isolation for high-power applications is presented. The design consists of a planar cavity, two 90° microstrip transmission lines, two matched loads, and one 180° microstrip transmission line. The cavity is fabricated using HMSIW structure and excited the TE101 mode at the centre frequency of 4.875 GHz. The external microstrip transmission lines and matched loads are added to improve the isolation between output ports. Moreover, the matched loads prevent the appeared heat loss in the substrate. The circuit behaviour is analysed based on the even and odd mode techniques, and the structure is simulated using a 3D EM simulator. The design is fabricated on a single-layer Rogers RO4003C, and a good agreement between the results of the simulation and measurement is observed. The measured results show that the proposed structure has the insertion loss of dB, and the isolation and output return loss better than 21.6 and 13.7 dB, respectively, when the return loss of the input port is better than 15 dB (4.8–4.95 GHz). This design has many advantages, such as low cost, low insertion loss, good return loss, good channels isolation, low profile, and compatibility with planar circuits.