Sensitivity analysis of a curved-structure rotary joint for a radar system in X-band

This paper deals with the design of a special kind of rotary joint that is used in a scanning slot antenna in a radar system. Because of the special structure of the system, we have used curved waveguides in our design. The radar system operates in X-band with a 200 MHz bandwidth where VSWR should not exceed a maximum value of 1.07. Simulation studies have been conducted to obtain the sensitivity of different parts of the rotary joint. The results show that the most sensitive parts of the device are the coaxial probes that should be manufactured with very high precision in order to get low VSWR in the desired bandwidth. We have used mode matching technique to analyze the waveguide discontinuities that has led to accurate results.