摘要:
A blower system to remove precipitation from an antenna may include a blower air plenum extending substantially completely along one side of the antenna. A vent is in communication with the blower air plenum and extends substantially completely along the one side of the antenna to direct an airstream across a surface of the antenna to remove precipitation from the antenna. The vent may include a contour to conform to a contour of the one side of the antenna. The blower system may also include an air compressor to force air into the blower air plenum and out the vent to form the airstream flowing across the surface of the antenna.
摘要:
A method of providing a communication link for a mobile platform. The method may involve generating a single beam and controlling the single beam to simultaneously generate first and second communication lobes from the single beam, with the first communication lobe being steered to communicate with a first base transceiver station (BTS). The method may further involve simultaneously using the second communication lobe to communicate with the second BTS and fading out the first lobe so that communication with the mobile platform is transferred to the second BTS.
摘要:
A blower system to remove precipitation from an antenna may include a blower air plenum extending substantially completely along one side of the antenna. A vent is in communication with the blower air plenum and extends substantially completely along the one side of the antenna to direct an airstream across a surface of the antenna to remove precipitation from the antenna. The vent may include a contour to conform to a contour of the one side of the antenna. The blower system may also include an air compressor to force air into the blower air plenum and out the vent to form the airstream flowing across the surface of the antenna.
摘要:
A method and apparatus for creating an antenna system. A configuration for a plurality of antenna cells is selected for an antenna in the antenna system. Each antenna cell in the plurality of antenna cells comprises a plurality of antenna elements having a symmetric arrangement. A portion of antenna elements in the plurality of antenna elements for each antenna cell in the plurality of antenna cells on a substrate is selected to transmit electromagnetic waves.
摘要:
A method and apparatus for identifying which one of a plurality of mobile terminals in communication with a ground-based base station, via a transponded satellite, is causing interference with a non-target satellite orbiting in a vicinity of the transponded satellite. The method involves using the base station to sequentially check each of the mobile terminals to identify which one is causing the interference. The check is made by the base station commanding each mobile terminal to modulate the power level of its transmitted signals and then checking with an operator of the interfered with non-target satellite to see if the interference condition has changed. Once the mobile terminal causing the interference condition is identified, the base station can command the mobile terminal to reduce its transmit power accordingly.
摘要:
An apparatus and method for correcting antenna beam misalignment between a transmit antenna and a receive antenna on a mobile platform such as an aircraft. The beam alignment method makes use of sequential lobing to determine the pointing angles in azimuth and elevation of a receive beam received by the receive antenna. For the transmit antenna, sequential lobing is used for the transmit antenna beam transmitted to a transponded satellite and then to a ground station. The ground station performs received signal strength indicator (RSSI) measurements and transmits these measurements back to the aircraft 16 via the target satellite. From these measurements, the beam misalignment between the receive and transmit antenna beams, both in azimuth and elevation, can be determined and a correction applied to the transmit antenna. The beam alignment procedure of the present invention can be implemented without interfering with normal use of the transmit and receive antennas and further ensures that interference with satellites adjacent to the target satellite will not occur during return link transmissions from the aircraft to the ground station.
摘要:
The corporate feed network employs light emitting opto-electronic components, such as laser diodes (12), connected together in a string (14) for distributing RF, microwave, MMW, digital signals, and pulse modulated light. Each diode provides two ports or facets which are coupled to optical fibers (16, 18) to connect to an active phased array antenna, for example. The diodes are selected in number and impedance to provide a good wideband impedance match to the RF/microwave/MMW/digital driving source. Multiple series strings of diodes may be employed, connected in parallel for larger corporate feed structures.
摘要:
A system and method for communicating information from a base station to one or more user terminals via a forward link to a relay and distribution device is provided. The method includes determining a separate information rate for information to be transmitted from the base station to each of the user terminals. Each information rate is determined to allow successful communication with the respective user terminal and to provide a predetermined amount of link margin above a threshold energy-to-noise ratio (Eb/No) in the forward link. The method additionally includes formatting data received at the base station into a continuous time division multiplexed (TDM) data stream that includes a plurality of data frames to be transmitted to the user terminals. Each data frame is formatted to have the determined information rate of the respective user terminal destine to receive the data frame. The TDM data stream is transmitted using a single carrier of the forward link. Furthermore, the method includes continuously and dynamically adjusting the information rate of subsequent data frames for each user terminal to maintain successful communication and maintain the predetermined amount of margin as operating conditions of each user terminal change.
摘要:
A system and method for managing access to a satellite-based transponder by a plurality of aircraft each having a mobile radio frequency (RF) system. The system employs a ground-based, central control system for managing access to the satellite-based transponder so that the aggregate power spectral density (PSD) of the RF signals of all the mobile systems does not exceed, at any time, limits established by regulatory agencies to prevent interference between satellite systems. This is accomplished by a dual control loop arrangement for monitoring the signal-to-noise ratio (Eb/No) of the RF signal transmitted by the satellite-based transponder. A ground-based control loop is used whereby a ground-based central controller monitors the Eb/No and transmits commands to the aircraft (via the satellite transponder) to maintain the Eb/No of the transmitted signal within a predetermined range. A fast scan angle compensation is used by the mobile system of the aircraft to implement another control loop to further adjust the transmit power. This control loop maintains the Eb/No of the signal transmitted to the satellite-based transponder at the commanded level inbetween updates from the ground-based central controller.
摘要:
A system and method for managing access to a satellite-based transponder by a plurality of aircraft each having a mobile radio frequency (RF) system. The system employs a ground-based, central control system for managing access to the satellite-based transponder so that the aggregate power spectral density (PSD) of the RF signals of all the mobile systems does not exceed, at any time, limits established by regulatory agencies to prevent interference between satellite systems. This is accomplished by a dual control loop arrangement for monitoring the signal-to-noise ratio (Eb/No) of the RF signal transmitted by the satellite-based transponder. A ground-based control loop is used whereby a ground-based central controller monitors the Eb/No and transmits commands to the aircraft (via the satellite transponder) to maintain the Eb/No of the transmitted signal within a predetermined range. A fast scan angle compensation is used by the mobile system of the aircraft to implement another control loop to further adjust the transmit power. This control loop maintains the Eb/No of the signal transmitted to the satellite-based transponder at the commanded level inbetween updates from the ground-based central controller.