Design and Simulation of Ultra High Power X-band Rotary Joint with a Matching Choke

In this paper, the design and simulation of an ultra-high power rotary joint for X-band frequency are discussed. The proposed rotary joint consists of a mode converter at the beginning and the end, a contactless circular waveguide, and an external choke including ball bearings and impedance-matching stubs in the middle part. At the beginning and the end parts, by converting the TE
10
mode of a rectangular waveguide to the TE
01
mode of a circular waveguide, a symmetrical mode is created, which enables successive rotations of the structure without disturbing the electrical current. The use of circular TE
01
mode in the proposed rotary joint leads to the power handling of 52 megawatts in the structure. The middle circular waveguide consists of choke and stubs for matching the contactless circular waveguide. The simulation results show that the proposed structure has a transmission loss of less than 0.4 dB and a return loss of better than 15 dB in the 10 GHz frequency.