24-07-2019 | Link Microtek Ltd | Subs & Systems
Link Microtek has produced an X-band microwave rotary joint to satisfy the notably demanding necessities of a satellite tracking system that transmits at a high pulsed power of 100kW, with a mean power of 4kW, over a wide frequency band of 2GHz.
Created to transmit and receive at frequencies from 8.5 to 10.5GHz, the tracking system employs long runs of WR90 rigid waveguide, with six of the special single-channel rotary joints offering the required movement for elevation, azimuth and tilt.
Steve Cranstone, managing director of Link Microtek, takes up the story: “While single-channel rotary joints in themselves aren’t particularly tough to make when you have that frequency bandwidth and those levels of power, it becomes a massive challenge.
“Any losses, even tiny ones, will generate a significant amount of heat, so thermal modelling was key in preventing internal overheating of the devices. What’s more, the customer’s system was unpressurised, so that made it very difficult to keep breakdown voltages to acceptable levels.”
Steve Cranstone again: “This project really pushed us to the limits of the power that can be handled in such relatively small waveguide size. You might expect to be dealing with a 100kW peak power level at lower frequencies, but at X-band, we had to be very, very careful to minimise the losses at every stage of design and production. Happily, our engineering team rose to the challenge, and the customer was delighted with the result.”
