The development of the Advanced Communications Technology Satellite (ACTS) Mobile Terminal (AMT) and its follow-on, the Broadband Aeronautical Terminal (BAT), have provided an excellent testbed for the evaluation of K- and Ka-band mobile satellite communications systems. An overview of both of these terminals is presented in this paper.

ACTS Mobile Terminals

A 20 GHz active receive slot array has been developed for operation in the downlink frequency band of NASA's Advanced Communication Technology Satellite (ACTS) for the ACTS Mobile Terminal (AMT) project. The AMT is used to demonstrate voice and data communication between a mobile terminal and a fixed terminal via the ACTS satellite. The active antenna consists of an array of fourteen linear series-fed-type microstrip slot arrays, fourteen packaged monolithic microwave integrated circuit (MMIC) low noise amplifier (LNA) submodules connected at each subarray output, a 14-way Wilkinson-type power divider, and a final additional LNA submodule used as a driver amplifier. The active receive array was designed to achieve the receive sensitivity requirement by placing the LNAs as close as possible to the antenna subarrays, minimizing the losses that occur in front of the amplifiers. The additional driver amplifier further minimizes the system G/T sensitivity to losses that follow the antenna. >

W. Chew

Papers

A 20 GHz active receive slot array