Abstract: A feed assembly for an antenna having a non-circular reflector, in which the feed assembly includes a feed horn capable of correcting the distortions of circularly polarized signals caused by the non-circular reflector profile, and wherein the feed horn is coupled with a polarizer that is field-switchable between linear and circular polarization modes of operation. The feed assembly can include a second receive-only feed located in close proximity to the feed horn for communication with adjacent satellites.

Abstract: The present invention provides a feed horn for use in an antenna assembly having a non-circular reflector. The feed horn is capable of transmitting and receiving circularly polarized signals. The feed horn includes a circular waveguide section for connection to a transmitter and receiver of the antenna assembly. A conical waveguide section is connected to an opposed end of the circular waveguide section for creating a smooth transition from the circular waveguide section to a non-circular corrugated waveguide section. The corrugated waveguide section includes a plurality of corrugations that transition for a circular shape adjacent to the conical waveguide section to an increasing non-circular shape at an end proximal to the reflector of the antenna assembly. The corrugations have individuals depths defined in the inner wall of the corrugated waveguide section. These depths compensate circularly polarized signals propagating in the feed horn for distortions due to the non-circular reflector.

Abstract: The present invention provides a feed horn for use in an antenna assembly having a non-circular reflector. The feed horn is capable of transmitting and receiving circularly polarized signals. The feed horn includes a circular waveguide section for connection to a transmitter and receiver of the antenna assembly. A conical waveguide section is connected to an opposed end of the circular waveguide section for creating a smooth transition from the circular waveguide section to a non-circular corrugated waveguide section. The corrugated waveguide section includes a plurality of corrugations that transition for a circular shape adjacent to the conical waveguide section to an increasing non-circular shape at an end proximal to the reflector of the antenna assembly. The corrugations have individuals depths defined in the inner wall of the corrugated waveguide section. These depths compensate circularly polarized signals propagating in the feed horn for distortions due to the non-circular reflector.

Abstract: The present invention provides antenna feed assemblies that allow the common waveguide portion of an antenna feed assembly to be rotated independent of a fixed communication waveguide. When rotated, the ports of the common waveguide are altered in terms of polarization with respect to signals propagating in the common waveguide, while the predetermined polarization between the ports remains the same. A rotatable coupling between the common waveguide and the fixed communication waveguide allows for communication of signals between the two waveguides, even though their ports are rotated with respect to each other. As such, the polarization of the waveguides associated with the antenna may be reconfigured, even though one of the waveguides remains at a fixed position.

Abstract: The present invention provides antenna feed assemblies that allow the common waveguide portion of an antenna feed assembly to be rotated independent of a fixed communication waveguide. When rotated, the ports of the common waveguide are altered in terms of polarization with respect to signals propagating in the common waveguide, while the predetermined polarization between the ports remains the same. A rotatable coupling between the common waveguide and the fixed communication waveguide allows for communication of signals between the two waveguides, even though their ports are rotated with respect to each other. As such, the polarization of the waveguides associated with the antenna may be reconfigured, even though one of the waveguides remains at a fixed position.

Abstract: A transmitting and receiving apparatus comprises a transmit/receive feed operable to transmit signals to and receive signals from a source, a waveguide assembly coupled with the transmit/receive feed for propagating transmitted and received signals to and from the transmit/receive feed, and a receive isolation filter coupled with the waveguide assembly and operable to filter the dual-polarized received signals without separating the two components thereof and to provide the filtered dual-polarized received signals to a receiver so as to isolate the receiver from signals transmitted by the transmit/receive feed. Thus, both components of the received signals are filtered simultaneously along the same path of propagation, eliminating the need to split the components along separate paths, separately filter them, and then recombine them as in prior antennas.

Abstract: Antennas and multiplexer structures are provided for establishing individual communication links with satellites that are located at geostationary positions in close angular proximity to one another. The antenna includes individual wave-guides where at least one of the wave-guides has a decreased dimension such that the wave-guides may be spaced in close proximity to each other to communicate with the satellites. For example, in one embodiment, the antenna includes at least one wave-guide that is a hollow metallic structure filled with a dielectric material. The dimensions of this wave-guide can be altered by changing the dielectric material used to fill the wave-guide. By using a dielectric material having an appropriate dielectric constant, the dimension of the wave-guide can be configured to allow the wave-guide to be spaced in close proximity to the other wave-guide.

Abstract: The present invention provides various wave-guides and support structures that are used in conjunction with feed structures to form compact antennas. Specifically, in one embodiment, the present invention provides a wave-guide design used for connecting the feed of an antenna to various electronics, such as a transmitter or receiver. The wave-guide of this embodiment includes a first end for connecting to the feed and a second end for connection to either a transmitter, receiver, or other electronic components. Importantly, the body of the wave-guide extends in a direction towards the reflector of the antenna so that the second end of the wave-guide is positioned closer to the reflector than the first end of the wave-guide. As such, the transmitter or receiver that is connected to the second end of the wave-guide is located in close relationship with the reflector, thereby creating a compact, aesthetically pleasing antenna structure.

Abstract: The present invention provides various wave-guides and support structures that are used in conjunction with feed structures to form compact antennas. Specifically, in one embodiment, the present invention provides a wave-guide design used for connecting the feed of an antenna to various electronics, such as a transmitter or receiver. The wave-guide of this embodiment includes a first end for connecting to the feed and a second end for connection to either a transmitter, receiver, or other electronic components. Importantly, the body of the wave-guide extends in a direction towards the reflector of the antenna so that the second end of the wave-guide is positioned closer to the reflector than the first end of the wave guide. As such, the transmitter or receiver that is connected to the second end of the wave-guide is located in close relationship with the reflector, thereby creating a compact, aesthetically pleasing antenna structure.

Abstract: An apparatus and associated method of manufacture for coupling a receiver and a transmitter to a single antenna feed horn so as to allow for the simultaneous transmission and reception of co-polarized signals, such as in a radio frequency communications system, are provided. To separate the two co-polarized signals of different frequencies, the apparatus comprises a waveguide junction, a first filter tuned to the transmit signal frequency, and a second filter tuned to the receive signal frequency. The apparatus may be manufactured using low-cost reusable-mandrel casting techniques.

Abstract: Antennas and multiplexer structures are provided for establishing individual communication links with satellites that are located at geostationary positions in close angular proximity to one another. The antenna includes individual wave-guides where at least one of the wave-guides has a decreased dimension such that the wave-guides may be spaced in close proximity to each other to communicate with the satellites. For example, in one embodiment, the antenna includes at least one wave-guide that is a hollow metallic structure filled with a dielectric material. The dimensions of this wave-guide can be altered by changing the dielectric material used to fill the wave-guide. By using a dielectric material having an appropriate dielectric constant, the dimension of the wave-guide can be configured to allow the wave-guide to be spaced in close proximity to the other wave-guide.

Abstract: An apparatus and associated method of manufacture for coupling a receiver and a transmitter to a single antenna feed horn so as to allow for the simultaneous transmission and reception of co-polarized signals, such as in a radio frequency communications system, are provided. To separate the two co-polarized signals of different frequencies, the apparatus comprises a waveguide junction, a first filter tuned to the transmit signal frequency, and a second filter tuned to the receive signal frequency. The apparatus may be manufactured using low-cost reusable-mandrel casting techniques.

Abstract: An antenna feed having a common circular waveguide with a longitudinally extending rectangular slot in a wall thereof and defining a receive port. An iris is rotatably connected adjacent the receive port permitting selective relative polarization of the transmit and receive signals. The relative polarization may be readily selected by a technician in the field without the need for changing antenna feeds when, for example, changing from co-polarization to cross-polarization. The iris includes a rectangular opening therein permitting the passage therethrough of the transmit signal while blocking the passage of a signal of the same frequency as the receive signal. The iris is positioned adjacent the receive port to enhance coupling of the receive signal into the receive port. The antenna feed provides high isolation between transmit and receive ports without the need for a filter on the transmit port.

Abstract: An antenna feed having a common circular waveguide with a longitudinally extending rectangular slot in a wall thereof and defining a receive port. An iris is rotatably connected adjacent the receive port permitting selective relative polarization of the transmit and receive signals. The relative polarization may be readily selected by a technician in the field without the need for changing antenna feeds when, for example, changing from co-polarization to cross-polarization. The iris includes a rectangular opening therein permitting the passage therethrough of the transmit signal while blocking the passage of a signal of the same frequency as the receive signal. The iris is positioned adjacent the receive port to enhance coupling of the receive signal into the receive port. The antenna feed provides high isolation between transmit and receive ports without the need for a filter on the transmit port.