Abstract: An antenna tower and support structure for use with an antenna tower, which allow a number of antennas or antenna panels to be mounted thereto, while maintaining the compactness of the overall structure and still providing high strength, such as is needed to resist high winds. The antenna tower includes an antenna support structure mounted to the antenna mast for supporting one or more antennas or antenna panels. The antenna support structure includes a bottom plate for mounting to the mast (or to another antenna support structure) and a top plate spaced from bottom plate. A beam with multiple webs extends between the bottom plate and the top plate. The beam includes a central post and a number of stiffening webs extending generally radially outwardly from the central post. The stiffening webs help to provide substantially greater stiffness against flexure and bending, without making the overall structure larger (or not much larger effectively).

Abstract: A class of modular, double-sided, edge-mounted printed circuit (PC) board modules and an associated modular network architecture for constructing stripline signal processing networks including high-power analog amplifiers and beam forming networks for driving multi-beam antenna systems. The stripline signal processing networks are characterized by network elements constructed from defined-length segments of transmission media configured to exhibit precisely determined phase and impedance characteristics. These circuits may also include conventional passive “lumped” electrical elements, such as resistors, capacitors and inductors; non-linear circuit elements such as diodes; and active electrical elements, such as amplifiers and transistors.

Abstract: A low-profile antenna system to be mounted to a moving vehicle for receiving signals, such as from a Digital Broadcast Satellite, includes a base for mounting to the surface of the vehicle, a platen mounted to the base for rotation, an azimuth drive motor for rotating the platen, an array of half-cylinder antenna elements mounted to the platen, an elevation drive motor for pivoting the antenna elements individually about their axes to change the elevation at which the antenna elements are pointing, and a cover. The azimuth drive motor and the elevation drive motor together allow the array of antenna elements to be pointed at a satellite over a wide range of vehicle orientations.

Abstract: A low-cost antenna array and method of manufacturing the array, in a planar form or in a structurally flexible or curved array structure are shown. The antenna array has a plurality of metallic antenna electrical and radiator elements formed on a foam core layer bonded onto a metallic ground layer. The radiator elements preferably are formed on a thin dielectric carrier layer bonded to the foam core layer. The array can include one or more additional dielectric layers, each with a plurality of parasitic radiator elements formed thereon, mounted on top of the electrical elements. Manufacturing the array preferably includes bonding the layers to one another. The electrical and radiator elements are formed, preferably by etching, before the foam core layer is bonded to the ground layer. The additional dielectric layer and the parasitic radiators then are bonded to the already formed electrical elements on the ground layer.

Abstract: One or more feedback elements generate a feedback signal in response to a transmitted signal outputted by each radiator of the antenna system. This feedback signal is received by each radiator, also described as a radiating element, and combined with any leakage signal present at the port of the antenna. Because the feedback signal and the leakage signal are set to the same frequency and are approximately 180 degrees out of phase, this signal summing operation serves to cancel both signals at the output port, thereby improving the port-to-port isolation characteristic of the antenna. Each feedback element can include a photo-etched planar metal strip supported by a planar dielectric card made from printed circuit board material. Such feedback elements can provide a high degree of repeatability and reliability in that the manufacturing of such feedback elements can be precisely controlled.

Abstract: An antenna system can generate RF radiation fields having dual simultaneous polarization states and having substantially rotationally symmetric radiation patterns. The antenna system generates RF radiation patterns where the beamwidths of respective RF fields for respective radiating elements are substantially equal and are relatively large despite the compact, physical size of the antenna system. The antenna system can include one or more patch radiators and a non-resonant patch separated from each other by an air dielectric and by relatively small spacer elements. The patch radiators and non-resonant patch can have predefined shapes for increasing polarization discrimination. The lower patch radiators can be mounted to a printed circuit board that can include an RF feed network and a ground plane which defines a plurality of symmetrically, shaped slots. The slots within the ground plane of the printed circuit board can be excited by stubs that are part of the feed network of the printed circuit board.

Abstract: A compact antenna system can generate RF radiation fields having increased beamwidths and bandwidths. The antenna system can include one or more patch radiators. The lower patch radiators can be mounted to a printed circuit board that can include a ground plane which defines a plurality of slots. The slots within the ground plane of the printed circuit board can be excited by stubs that are part of the feed network of the printed circuit board. The slots, in turn, can establish RF radiation in a cavity which is disposed adjacent to the ground plane of the printed circuit board and a ground plane of the antenna system.

Abstract: An improved multi-junction waveguide circulator that eliminates the transitions to dielectric transformers and air-filled waveguides between ferrite elements is described. The waveguide circulator in accordance with the invention can be implemented in variations from a minimum of two ferrite circulator elements held in close proximity to one another to any number of ferrite elements as required to achieve the desired isolation performance or to create a switch matrix with any combination of input and output ports. The waveguide circulator in accordance with the invention eliminates the transitions between adjacent ferrite elements and thus reduces losses, component size, and mass.

Abstract: A dual-polarization wireless base station antenna that implements vertical electrical downtilt and sidelobe reduction using beam steering circuit that includes a variable power divider and a multi-beam beam forming network. The variable power divider includes a single adjustable control element to divide an input voltage signal into a pair of complimentary amplitude voltage drive signals that exhibit matched phase and constant phase delay through the variable power divider. The beam forming network is configured as a double-sided, edge-connected microstrip module mounted to a main panel, which support the antenna elements in a vertical column organized into sub-arrays in a manner that implements sidelobe reduction. The power distribution network connecting the beam steering network to the antenna elements implements beam tilt bias and sidelobe reduction through coordinated phase shifting implemented through transmission media trace length adjustment.

Abstract: A variable power divider and method can vary the RF power between ports in a high power and multi-carrier RF environment, such as is used in controlling signals sent and received in a base station antenna. The variable power divider can include a single-control phase shifter and a hybrid power divider. The single-control phase shifter can comprise a three-port device having a single input port and two output ports. The single-control phase shifter can further comprise a variable adjuster that can change or adjust the phase between two RF signals. The hybrid power divider can comprise a four-port device having two input ports and two output ports. Both the single-control phase shifter and the hybrid power divider can comprise substantially planar structures that are suitable for high-speed manufacturing. The output ports of the hybrid power divider can be coupled to various devices such antennas or power absorbing elements.

Abstract: A spot beam satellite communications system and method for delivering information to user terminals at a high data rate. In a hub, a high data rate serial data stream is separated into parallel data streams that are modulated onto respective uplink transponders. The uplink transponders are transmitted by the hub to an earth-orbiting satellite, which translates the uplink signals to downlink frequencies. The satellite broadcasts the transponders to user terminals located in the desired beam coverage areas on the earth. The user terminal separates the downlink transponders and demodulates each of the downlink transponder signals to regenerate the parallel data streams. The parallel data streams are combined to reproduce the original serial data stream. By dedicating multiple transponders to a particular data stream, data can be relayed at a very high data rate by a communications satellite that employs a standard transponder frequency assignment scheme.

Abstract: A dual-band antenna suitable for use in a cellular telephone network base station includes two parallel arrays of low-frequency dipole elements disposed on a ground plane, a raised array of high-frequency dipole elements disposed between the two parallel arrays, and at least one beamforming rod disposed between the raised array and the two parallel arrays. The two parallel arrays operatively form symmetric azimuth radiation patterns in a lower range of frequencies. The raised array and the high frequency beamforming rod likewise operatively form symmetric azimuth radiation patterns in a higher range of frequencies. This configuration of dual-band antenna allows reception and transmission of electromagnetic signals in two discrete frequency bands while occupying a compact space.

Abstract: A variable power divider and method can vary the RF power between ports in a high power and multi-carrier RF environment, such as is used in controlling signals sent and received in a base station antenna. The variable power divider can include a single-control phase shifter and a hybrid power divider. The single-control phase shifter can comprise a three-port device having a single input port and two output ports. The single-control phase shifter can further comprise a variable adjuster that can change or adjust the phase between two RF signals. The hybrid power divider can comprise a four-port device having two input ports and two output ports. Both the single-control phase shifter and the hybrid power divider can comprise substantially planar structures that are suitable for high-speed manufacturing. The output ports of the hybrid power divider can be coupled to various devices such antennas or power absorbing elements.

Abstract: A phased array antenna system operative to broadcast multiple beams that each include coded data for specific users located within the coverage area of the corresponding beam. An appropriate receiver then receives and decodes a particular beam to extract the specific data for a corresponding user. Multiple users may be assigned to each beam using frequency division or orthogonal code multiplexing, and the user data may be encoded into the beams using frequency shift key or phase shift key encoding. For each coding technique, the encoded antenna control signals are combined into a total gain and total phase shift control signal, which drives a single phase and gain control device for each antenna element. In addition, a single data modulator generates the coding parameters for the entire communication system.

Abstract: A phased array antenna system that is operative to simultaneously form multiple beams without requiring an undue amount of hardware. The system collects propagating energy with a number of antenna elements to form multiple beams, encodes the beams as the energy is collected, combines the encoded beams, and then decodes the combined signal to separate the beams. In this way, the beams can be formed with a single set of antenna hardware instead of requiring a multiplicity of antenna hardware, one for each beam. Frequency coding may be implemented by repeatedly applying a Doppler phase shift to each beam, and then using a Doppler filter to separate the beams. Alternatively, a code division multiplexing technique may be implemented by using a CDMA code generator to apply a code to each beam, and then using a CDMA filter to separate the beams.

Abstract: A satellite communications system having ground user terminals, hubs, and a geosynchronous satellite. The satellite generates a network of spot beam coverage areas on the earth. A hub and at least one ground terminal are located in each of at least two spot beams. A first user terminal transmits an uplink signal according to a first signal protocol to the hub through the satellite. A second user terminal receives a downlink signal according to a second signal protocol through the downlink spot beam from the hub through the satellite. The hub may be located in the same spot beam coverage area as the first or the second user terminal or may be located in an altogether different spot beam coverage area.

Abstract: A low-cost user portable signal enhancer unit for extending service coverage of wireless communications to a user in a desired area of limited coverage. The enhancement supports an increase of signal power levels to allow wireless communication usage in a location, such as a small office or home office environment where the original cellular signals are weak or unreliable. A base station signal is enhanced by a bi-directional amplifier device (BDA), which receives a base station signal, amplifies the signal power and retransmits the amplified signal in a first signal path to a user in close proximity. The bi-directional amplifier also receives a user signal, amplifies the signal power and retransmits the amplified signal to the base station in a second separate signal path. Dual polarized antennas can receive and transmit the respective signals at opposite polarizations to increase isolation of the signals.

Abstract: A low-cost antenna array and method of manufacturing the array, in a planar form or in a structurally flexible or curved array structure are shown. The antenna array has a plurality of metallic antenna electrical and radiator elements formed on a foam core layer bonded onto a metallic ground layer. The radiator elements preferably are formed on a thin dielectric carrier layer bonded to the foam core layer. The array can include one or more additional dielectric layers, each with a plurality of parasitic radiator elements formed thereon, mounted on top of the electrical elements. Manufacturing the array preferably includes bonding the layers to one another. The electrical and radiator elements are formed, preferably by etching, before the foam core layer is bonded to the ground layer. The additional dielectric layer and the parasitic radiators then are bonded to the already formed electrical elements on the ground layer.

Abstract: A variable power divider and method can vary the RF power between ports in a high power and multi-carrier RF environment, such as is used in controlling signals sent and received in a base station antenna. The variable power divider can include a single-control phase shifter and a hybrid power divider. The single-control phase shifter can comprise a three-port device having a single input port and two output ports. The single-control phase shifter can further comprise a variable adjuster that can change or adjust the phase between two RF signals. The hybrid power divider can comprise a four-port device having two input ports and two output ports. Both the single-control phase shifter and the hybrid power divider can comprise substantially planar structures that are suitable for high-speed manufacturing. The output ports of the hybrid power divider can be coupled to various devices such antennas or power absorbing elements.

Abstract: A satellite communications system having ground user terminals, hubs, and a geosynchronous satellite. The satellite generates a network of spot beam coverage areas on the earth. A hub and at least one ground terminal are located in each of at least two spot beams. A first user terminal transmits an uplink signal according to a first signal protocol to the hub through the satellite. A second user terminal receives a downlink signal according to a second signal protocol through the downlink spot beam from the hub through the satellite. The hub may be located in the same spot beam coverage area as the first or the second user terminal or may be located in an altogether different spot beam coverage area.