A Novel Low Profile Rectangle Waveguide Planar Magic-T of Ka-Band

With the research and application of monopulse antenna, Sum and Difference become an essential element. As the basic component, the magic-T should be paid attention to. Due to the drawback of large profile in traditional magic-T, one planar magic-T structure working at the Ka- band have been designed and simulated in this letter. The F-arm fed through a longitudinal coupling gap in the proposed structure is coplanar with other arms for saving valuable space in a minimization device such as Sum and Difference network. In order to fine return loss properties, one copper cylinder is added act as inductance element to disturb the electromagnetic field for improving impedance matching. As a result, the bandwidth (VSWR<1.45) with 4 GHz is obtained at the resonance frequency of about 35.5 GHz. The performance of low loss, equal power divide, Low VSWR and high isolation have all been achieved and it is of significance in design sum-and-difference network which can work in Monopulse antenna acting as feeding network.