Abstract: A dynamic method for optimizing interference levels between multiple downlink beams transmitted from a satellite with a common frequency spectrum causes the power level of at least one of the interfering beams to be adjusted so as to produce desired interference levels within the beams' respective ground target areas. The beam power adjustments are preferably accomplished by varying the drive levels of the high power amplifiers on board the satellite, at least one of which is initially operated at less than its maximum rated power level. Single or multiple beam powers can be adjusted, either up, down or some up and some down. Power level adjustments are normally made in response to actual beam power profiles not matching design standards, to changing service priorities among the different beam target areas, and to changing signal power requirements for the different beams.

Abstract: The new satellite communications repeater test method allows multiple transponders to be tested from a single ground test station. The satellite's receive antenna is aligned with the ground station antenna and uplink test signals are transmitted to the satellite. The uplink test signal is converted to a corresponding downlink signal which is distributed to the transponders fed by the receive antenna. Prior to transmission from the satellite, the amplified downlink signals are sampled and combined and/or switched into a single path having a frequency spectrum which includes the frequency bands of the sampled downlink signals. The combined signal is transmitted to the ground test station from a wide angle transmit antenna. The received downlink signals are measured and stored for later processing to validate the operational characteristics of the transponders. In an alternative embodiment, the sampling and combining matrix includes switches for selecting the sampled signals to be combined.

Abstract: The number of high power amplifiers required for multi-channel satellite communications is reduced by a high power amplification of selected sets of signals in respective common amplifiers, with each set of combined signals consisting of channels whose frequency bands are mutually discrete and sufficiently separated in frequency that their third order intermodulation products do not substantially overlap in frequency with any of the channels in the same set. The signals can be separated out again after amplification and transmitted as downlink signals, either individually from a dedicated downlink antenna or in combination with other channels in a common downlink antenna.

Abstract: A method of testing in-orbit communications satellite receive antennas from a single ground test station. The ground test station transmits an uplink test signal to the orbiting satellite. Telemetry circuitry onboard the satellite measures the power level of the uplink signal received and converts it to a corresponding digital value. The satellite's position is slewed over angles approximately covering the receive antenna areas of reception. The power level of the received uplink test signal and satellite orientation information are transmitted to the ground test station in the satellite's telemetry data stream. A computer at the ground test station plots the power level with respect to the satellite's corresponding orientation to map the receive antenna pattern. In an alternative embodiment, a plurality of receive antennas are tested simultaneously.