Communications: directive radio wave systems and devices (e.g. – Directive – Including a steerable array
Reexamination Certificate
1999-09-16
2001-07-24
Tarcza, Thomas H. (Department: 3662)
Communications: directive radio wave systems and devices (e.g.,
Directive
Including a steerable array
Reexamination Certificate
active
06266010
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to systems for transmitting and receiving information, and more particularly, to antenna systems for transmitting and receiving signals using electronic beam forming. Exemplary embodiments are applicable to any situation where antennae are used including, but not limited to, any communication systems that involve wireless transmission or reception of signals.
2. Background Information
Antenna systems for transmitting and receiving information are used for a variety of applications, including wireless communication system applications and radar applications which involve object detection and tracking. These antenna systems are typically configured to accommodate the sequential channel processing associated with low cost radio frequency (RF) seeker applications (that is, object detection and tracking), among other radar applications.
A typical antenna system suitable for these radar applications is a cassegrain antenna system, wherein the antenna includes multiple output ports. A conventional cassegrain antenna system also includes waveguide material, known in the art as a “magic T”, to passively (that is, without electronic components) provide multiple antenna system outputs. For example, a typical four channel cassegrain antenna supplies A, B, C and D signals from the antenna output ports to the waveguide material of the antenna system. The waveguide material can be a plurality of magic T's. The waveguide material includes a plurality of antenna system ports, which can provide or receive the variety of signals that are of interest to various applications for which the antenna is to be used.
For example, output signals from the waveguide material can include a summed output signal: A+B+C+D, and a differential output signal: A+B−C−D or A+C−B−D. The summed output signal and the differential output signal can be combined in a transceiver to provide, for example, monopulse indications of the azimuth and elevation of an object to be detected and/or tracked.
Because the cassegrain antenna system uses waveguide material to produce output signals of interest at a plurality of separate antenna system ports, a transceiver which receives the signals to produce the azimuth and elevation information, or which supplies signals to the antenna, must be configured as a multichannel transceiver. The transceiver must have a separate channel for each port of the antenna system's waveguide material to provide the desired active and passive tracking functions for which the antenna system is to be used. These multichannel transceivers are complex and costly because of the active components they require to provide the multichannel functionality. Moreover, each of the multichannel paths in the transceiver must be calibrated independently, and repeatedly recalibrated to ensure accurate, reliable operation, thus adding to the cost and complexity of the transceiver.
Accordingly, it would be desirable to provide an antenna system for receiving and transmitting signals which is suitable for a variety of applications including, but not limited to, communication systems and radar systems, but which does not require the associated transmitter, receiver or transceiver to possess the hardware, high cost and circuit complexity of conventional systems.
SUMMARY OF THE INVENTION
The present invention is directed to providing an antenna system for transmitting and receiving signals in a manner which eliminates the extensive hardware, high cost and complexity of the transmitter, receiver or transceiver used in conventional systems. Exemplary embodiments are directed to an antenna system which uses electronic beam forming to mathematically synthesize the signals desired for reception or transmission. Rather than using passive waveguide material having multiple antenna system ports that must be individually processed in separate transceiver channels, exemplary embodiments of the present invention are directed to an antenna system wherein the antenna ports are coupled to a beam forming network of the antenna system. The beam forming network includes a single port that can be coupled to a single transceiver channel.
The beam forming network is configured to mathematically synthesize each of the desired signals needed by the transceiver to calculate desired information, such as the azimuth and elevation of an object to be detected and/or tracked (for example, the summed output signal and a difference output signal). The beam forming network can be configured to sequentially produce each of the desired signals. Alternately, the beam forming network can provide desired signals from the transceiver channel to the multiple antenna ports during a transmit operation.
Exemplary embodiments are applicable to any systems which involve the use of an antenna systems, including, but not limited to, communication systems and radar applications. Exemplary embodiments can provide any of the functionality typically associated with beam forming antennae including, but not limited to communications such as satellite to ground communications, beam shaping, and beam pointing.
Generally speaking, exemplary embodiments of the present invention relate to a method and associated apparatus for at least one of transmitting and receiving signals. Exemplary embodiments include, among other features, an antenna having a plurality of antenna ports; and a beam forming means for sequentially interfacing said plurality of antenna ports to a single antenna system port, said forming means being reconfigurable to synthesize signals at one of said plurality of antenna ports and said single antenna system port from signals at the other of said plurality of antenna ports and said single antenna system port. The single antenna system port can be coupled to a transmitter or receiver configured with a single channel for interfacing with the beam forming means.
REFERENCES:
patent: 4032922 (1977-06-01), Provencher
patent: 4499472 (1985-02-01), Willett
patent: 4626858 (1986-12-01), Copeland
patent: 4893126 (1990-01-01), Evans
patent: 5115245 (1992-05-01), Wen et al.
patent: 5486832 (1996-01-01), Hulderman
patent: 5495255 (1996-02-01), Komatsu et al.
patent: 5657024 (1997-08-01), Shingyoji et al.
patent: 5684491 (1997-11-01), Newman et al.
patent: 5691729 (1997-11-01), Gutman et al.
Ammar Danny F.
Brady Vernon
Burns Doane , Swecker, Mathis LLP
Lockheed Martin Corporation
Mull Fred H.
Tarcza Thomas H.
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