Double Ridged 180 $^{\circ}$ Hybrid Power Divider With Integrated Band Pass Filter

We describe the design, construction and performance of a 180° hybrid power divider with integrated band pass filter for L-band (1.3-1.8 GHz). The hybrid is based on a cavity and two novel broadband coaxial-to-double ridged waveguide transitions. The design was optimized using a commercial 3-D electromagnetic simulator. The device was tested at room and cryogenic temperature. At the physical temperature of 77 K the measured input reflection was less than -17 dB, the maximum deviation from the ideal -3 dB coupling and 180° phase difference were, respectively ±0.25 dB and ±0.9°. The experimental results are in good agreement with simulation.