Microwave Journal
Link Microtek

Link Microtek's Integrated RJSA Lowers Profile of Ka-Band SOTM Systems

September 17, 2018

Link Microtek has introduced a compact new integrated rotary joint and slip-ring assembly (RJSA) for use in the stabilised antennas of both commercial and military Ka-band satellite-on-the-move (SOTM) communication systems.

These systems are deployed on mobile ground vehicles, ships or aircraft to provide broadband network access for high-data-rate applications such as real-time high-definition video or transmission of telemetry data.

By combining the functions of the microwave rotary joint and slip ring into one device, the new AM28RJDSR integrated assembly helps SOTM system manufacturers with the key design consideration of minimising the height of their antenna radomes.

This dual-channel unit uses a central 27.5 to 31 GHz channel, implemented in WR28 waveguide and K-type coax, for transmitting RF signals with a power of up to 40 W, while a DC to 2.15 GHz SMA coaxial outer channel is provided for L-Band receive signals. The integrated slip ring conveys electrical power from the SOTM system’s stationary pedestal to components on the rotating side, including motors, encoders and GPS receivers.

The RJSA offers excellent microwave performance, with a VSWR of 1.3:1 and a typical insertion loss of just 0.5 dB on the transmit channel. The receive channel has a power rating of 1 W, a VSWR of 1.5:1 and a typical insertion loss of 0.4 dB. Isolation between the channels is specified as -25 dB.

Designed for lock-on and dither operation with 360 degree rotation in both directions, the device is fabricated from lightweight aluminium and is suitable for use in ambient temperatures ranging from -40oC to 60oC.

In addition to the AM28RJDSR, Link Microtek is able to offer RJSAs to meet customers’ particular requirements including, for example, configurations suitable for Ku- and X-Band applications.