Loopback radio frequency translator for the ACTS Mobile Terminal

The ACTS Mobile Terminal (AMT) is a ground based mobile satellite communications terminal designed to operate with the NASA Advanced Communications Technology Satellite (ACTS). With a scheduled launch in mid-1993, propagation experiments will begin in late 1993. This will be done to characterize the communications path between a fixed communication site in Cleveland, Ohio and a mobile terminal in Southern California via ACTS. The terminal uplink frequency is 29.634 GHz±150 MHz and the downlink frequency is 19.914 GHz±150 MHz. A pilot signal at 29.630 GHz will be transmitted from the fixed site for antenna tracking by the mobile terminal. This paper summarizes the system design and performance measurements of the Loopback Translator, a satellite simulator to be used in testing the fixed and mobile terminal hardware prior to the ACTS launch. The Translator provides full duplex, single stage up and down conversion between the 3.373 GHz Intermediate Frequency (IF) and the transmit/receive frequencies