Multi-Band Rotary Joint for Antenna Feeds/Waveguides

Millitech has a high level of expertise in the design of millimeter-wave hardware and has long been in the business of exacting the maximum amount of performance out of a minimum of volume, mass, and available power, in our component and system designs for the space community. We have a potential solution for the rotary joints for the particular case of the subHDR system upgrade, which can be designed during phase I, and built and tested during phase II. The design of the elevation and cross-elevation rotary joints will use a unique combination of low-loss coaxial line, terminated with a non-contacting waveguide transition on each end. The coaxial line will replace a circular waveguide TM01 line, which trades off power handling for bandwidth. By optimizing the size of the coax, however, the power handling is still 41.7 kW, a factor of 16X the power currently planned for the system, with comparable loss to the current design. The train rotary joint will use a similar technique for the upper frequency bands and a novel non-contacting scheme for the X band circuit path, rather than the current slip ring, enhancing the reliability considerably as well as reducing the cost of the part.