Design of ultra-wideband Magic-T using microstrip/slot coupler and phase shifter

Abstract

A broadband Magic-T using 3-dB coupler and 90° phase shifter is proposed in this paper. Microstrip/Slot technology has been employed in the design. Compared with the conventional magic-T, it can operate over an ultra-wideband. Results of simulation and measurement show that the relative bandwidth is 105 % with the VSWR less than 1.85, and the insertion loss less than 1.6 dB. The phase ripple is ±12°. The isolation is greater than 13dB across 2.5-8GHz.