W-band 30 dB Waveguide Directional Coupler with H-plate Slot Bridge Structure

This paper presents a W-band 30dB broadband waveguide directional coupler with H-plate slot bridge structure, which shows good bandwidth characteristics. By proposing a sandwich-like three-layer structure, the reliability of the device is improved. A sample of the proposed coupler is tested. In the range of 75 - 110 GHz, the measured return loss is better than 20dB, the isolation is better than 30dB, the coupling is 30 ± 1.5 dB, and the average insertion loss is 0.17 dB. The experimental results are in good agreement with the simulation results.