INTEGRATED ANTENNA AND RF PAYLOAD FOR LOW-COST INTER-SATELLITE LINKS USING SUPER-ELLIPTICAL ANTENNA APERTURE WITH SINGLE AXIS GIMBAL

摘要

A dual-reflector inter-satellite link (ISL) subsystem, for a communications satellite in a constellation of satellites in low earth orbit or medium earth orbit, is disclosed. The ISL subsystem includes a main antenna reflector which uses a single-axis gimbal to steer the main reflector only in the elevation plane. An antenna subreflector, a horn and RF feed circuitry are stationary with respect to the host satellite. The main reflector has a super-elliptical design which provides a beam shape which requires no steering in the azimuth plane, while meeting ISL signal strength requirements. By steering the main reflector only, and only in the elevation plane, the disclosed ISL subsystem delivers significantly lower size, mass, complexity and cost, and significantly greater reliability, than traditional ISL systems.

主权项

1. An inter-satellite link (ISL) subsystem for a communications satellite, said ISL subsystem comprising:
a main reflector having a super-elliptical shape and an elongated central opening; a mounting plate fixed to a back side of the main reflector, said mounting plate also having an elongated central opening; a single axis gimbal motor including a motor mount which mounts the motor to a chassis of the communications satellite; a pivot arm attached at a first end to an output shaft of the motor, said pivot arm being attached at a second end to the mounting plate such that a rotation of the output shaft of the motor causes the main reflector to tilt; a radio frequency (RF) feed circuit contained in an electronics housing, where said electronics housing is mounted to the chassis; a feed cone mounted to the electronics housing, said feed cone having a generally tubular shape and positioned where it passes through the central openings of the main reflector and the mounting plate; a horn in communication with the RF feed circuit, said horn sending and receiving RF signals to and from a remote satellite, where the horn is positioned inside the feed cone; and a subreflector mounted via a plurality of struts to the feed cone and centered on an axis of the feed cone, where the RF signals radiate from the horn to the subreflector to the main reflector to the remote satellite, and vice versa, and a beam of the RF signals is steered in an elevation plane only via tilting of the main reflector by the motor.