A 34.5GHz planar magic-T based on coupling slot and substrate integrated waveguide

In this paper, a ka-band magic-T using substrate integrated waveguide (SIW) and coupling slot is proposed and developed for microwave applications on the basis of the substrate integrated waveguide (SIW) technology. Due to the metal ground between the input and output ports the planar magic-T consists of a 180 degree phase-reversal junction and an H-plane SIW T-junction. Theoretical analyses and the optimized wideband magic-T structure is demonstrated and discussed with the models of the magic-T. The magic-T is simulated with a 3D FEM electromagnetic simulation software and the results are presented. The frequency bandwidth is 20.3%, when the simulated VSWR of the port of the magic-T is less than 1.5 from 31GHz to 38GHz, and the simulated amplitude imbalance is less than ±0.22dB, and the simulated phase imbalance is less than ±0.8°, and the simulated isolation between the sum port and the difference port is higher than 43dB.