Antenna positioner for portable satellite terminal

Abstract

A motorized antenna positioning mechanism in a portable microwave communication unit for use as a ground station in a satellite communication system. The antenna positioner has compact and low profile azimuth wire drive mechanics, azimuth and polarization angle sensors that are not affected by slippage and backlash, and an elevation drive mechanism which neutralizes the pressure on the motor axis due to the weight of the parabolic antenna.

Description

RELATED APPLICATIONS [0001] The present application claims the benefit of U.S. patent application Ser. No. 11 / 220,549, filed Sep. 8, 2005.FIELD OF THE INVENTION [0002] The present invention relates to antenna positioning systems in certain types of portable terminals for satellite communications where automatic, rather than manual, alignment to the desired satellite is preferred. BACKGROUND OF THE INVENTION [0003] Typically, such terminals are found in Satellite News Gathering (SNG) and in some military communication systems. Because of the performance required, terminals of this kind are not intrinsically very small, as parabolic antennas around 1m in diameter are needed. This, in conjunction with the automatic acquisition feature, results in certain mechanical and electrical requirements on the positioner that this invention solves in a novel way. [0004] In antenna positioners, or positioning systems, the mechanisms for adjusting the azimuth, elevation and polarization angles are ...

AI Technical Summary

Benefits of technology

"The invention is a motorized antenna positioner for small portable satellite terminals that improves in the azimuth, elevation, and polarization mechanisms. The improvements include an azimuth drive with a crossed cable and a driving pulley for better traction, an elevation adjustment mechanism with a de-coupling feature, and a polarization adjustment mechanism with a circular potentiometer for better accuracy and resolution. The invention also includes an elevation drive with a bearing and a motor axle, and a polarization adjustment drive with an angular sensor for improved accuracy and resolution. The invention is flat and compact, with a low profile that can be easily incorporated into the terminal's electronics."

Problems solved by technology

In addition to the purely mechanical aspects, there is also the issue of angular sensors for azimuth, elevation and polarization.

Further, the disadvantage of the above solutions is that the multi-turn devices used result in relatively big (deep) structures compared to the simple one-turn pulley and drum combination.

One of the problems in motorized elevation adjustment structures is the pressure exerted on the motor axle due to the weight of the antenna, pushing downwards, or pulling upwards, depending on the elevation angle.

This can have a negative effect on the performance and reliability of the motor.

The patents mentioned above, concerned primarily with mechanics, do not address this.

The disadvantage of the above solutions is the relatively low accuracy and resolution of regular potentiometers and the potential slippage or backlash depending on the method of mechanical coupling to the potentiometers.

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