A novel low profile high power Ka-band planar Sum and Difference Network

This letter introduces a Sum and Difference Network working at the centre frequency of 35.5GHz of Ka-Band. The Monopulse radar needs to be fed with the Sum and Difference Network for its requirement for sum and difference signals. Due to the requirement for sum and difference signals, the Monopulse radar was added to be fed with the Sum and Difference Network In this paper, the proposed structure adopts a kind of planar Magic-T with its E-arm bent to the parallel side and the E-arm is fed through a longitudinal coupling gap. This structure working at the center frequency of 35.5GHz is impedance bandwidth and can be up to 2 GHz for 10-dB return loss. Nonstandard waveguide is employed to get better performance. Furthermore, to get better impedance performance, four metal cylinders is used in this structure. The waveguide Sum and Difference has the merits of small in size and high power capacity, thus it is promising in radar system.