Comsat Corporation

Other

John I Upshur

Francois T Assal

Bernard D Geller

Donald Stuart Arnstein

Albert Edward Williams

Mohammed Mahbubur Rahman

Moshe Lieberman

Asynchronously-tuned coupled resonator cavities are implemented having a minimum set of inter-resonator couplings, wherein the filter design incorporates only series and parallel couplings. By way of example, 8 order filter topologies having three transmission zeros, no cross-couplings, and only eight series and/or parallel couplings can be achieved.

Asymmetric response bandpass filter having resonators with minimum couplings

A method and apparatus to enable high-quality digital transmissions to a satellite terminal operating in proximity to a radar source combines interleaving a sequence of channel symbols at a land station before transmission of an RF signal to a satellite, increasing the satellite's EIRP to compensate for the effects of the radar's duty factor on received signal power and code distance, detecting the radar pulses at a satellite terminal, blanking the received RF signal to prevent reception of the signal by the modem at the satellite terminal during the radar's ON time, having the modem recognize and eliminate the effect of the gap in the channel signals on its metric calculation, and de-interleaving the sequence of channel symbols. As a result, satellite terminals operating in proximity to radar sources can provide the same quality of service as if there were no radars operating.

Low noise front-end blanking and interleaving for satellite reception in

A low loss reflection-type analog phase shifter circuit producing a large range (nearly 360.degree.) of phase shift at X-band while achieving low attenuation (insertion loss) and little amplitude variation over all phase states. The results are achieved, in part, by using a terminating impedance which includes parallel-connected hyperabrupt varactor diodes. The circuit is implemented readily in a monolithic microwave integrated circuit using GaAs.

Low loss 360 degree X-band analog phase shifter

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Germantown, MD, United States of America

John I Upshur