摘要:
An active array system with electronic roll stabilization of the difference patterns, and with arbitrary partitioning of the phase scanned aperture with no hardware changes. The array system comprises a large number of radiating elements forming the array, with individual transmit/receive active modules coupled to each radiating element. In each active module, the received signal is amplified and then divided (164) into three signal components. Two of the signal components are passed through a bi-state phase shifter (166, 168) for selectively phase shifting the signal component by 0 to 180 degrees. The selectively phase shifted receive signals are then coupled to the respective azimuth and elevation difference channels (92, 93). The third signal component is coupled to the sum channel (91) network. The respective sum and difference channels all provide summing functions on the respective sum and differnce signals from each module. The phase shifters provide an output signal with either a positive or negative sign, so that in effect the module signals are ''differenced'' first and then summed.
摘要:
The present invention relates to a system 10; 20 for mast vibration compensation implemented in communication system including a first nod and a second node. The first node comprises a first adaptive antenna 11; 2 mounted in a mast; a receiver 12; 22 connected to said antenna 11; 21; an a spatial and temporary processing system 15; 25. The first adaptive antenna 11; 21 is controlled by a first correction signal generated in the spatial and temporary processing system 15; 25. The correction signal is based on a parameter that indicates that a radio link alignment with a second node is degrading due to mechanical vibrations in the mast. The invention also relates to a method for mast vibration compensation.
摘要:
An antenna for communicating with a satellite from a moving vehicle. The antenna comprises a transmitter for generating a transmission signal, main and sub reflectors, and a waveguide associated with the transmitter for conducting the transmission signal toward the sub reflector. The sub reflector is configured for redirecting the transmission signal toward the main reflector; the main reflector is configured for projecting the redirected transmission signal as an antenna beam toward the satellite.
摘要:
A robust antenna tracking system apparatus (10) is capable of quickly and accurately tracking satellites without the use of a compass under adverse conditions while being subjected to large torque stress and being weatherproof. The apparatus can be attached to a ship or land vehicle and can be used while the vehicle is in motion. Upon the customer choosing a satellite from which to receive signals (202), the invention acquires a satellite by scanning the sky to locate a system labeled primary satellite (204). The identification of the system labeled primary satellite is accomplished by comparing the leading and falling edges of rf-signal pulse (220a), comparing beacon signal transmissions (220b), comparing the relative positioning of other satellites (220c), or determining the angle of elevation of the satellite relative to the horizon (220d). Upon identifying the system labeled primary satellite, the customer chosen satellite is located by calculating its position relative to the system labeled primary satellite (300, 302), and then verifying (306) the customer chosen satellite through on the four identifying means used for the system labeled primary satellite (220a, 220b, 220c and 220d). Satellites are tracked by measuring the increase and decrease in signal strength (308, 310a and 310b) as the antenna is moved a known distance within the satellite's range.
摘要:
La présente invention concerne un dispositif (10) d'orientation d'un élément mobile, comportant : un bâti (12), un élément (16) mobile par rapport au bâti, au moins trois articulations (22, 46, 48) reliées à l'élément mobile, et au moins deux actionneurs linéaires (26, 28) comprenant chacun un corps (30, 32) et une tige (34, 36) mobile, une première extrémité de chaque tige étant reliée à l'une des trois articulations, chaque corps étant monté en rotation (38, 40) sur le bâti. Deux des actionneurs linéaires sont des moteurs linéaires à tige traversante et une seconde extrémité (50, 52) de chaque tige est apte à se déplacer à l'intérieur d'une cavité (42, 44) ménagée dans le bâti.
摘要:
A rotationally-stabilizing tracking antenna system suitable for mounting on a moving structure includes a three-axis pedestal for supporting an antenna about a first azimuth axis, a second cross-level axis, and a third elevation axis, a three-axis drive assembly for rotating a vertical support assembly relative to a base assembly about the first azimuth axis, a cross-level driver for pivoting a cross-level frame assembly relative to the vertical support assembly about the second cross-level axis, and an elevation driver for pivoting an elevation frame assembly relative to the cross-level frame assembly about the third elevation axis, a motion platform assembly affixed to and movable with the elevation frame assembly, three orthogonally mounted angular rate sensors disposed on the motion platform assembly for sensing motion about predetermined X, Y and Z axis of the elevation frame assembly, a three-axis gravity accelerometer mounted on the motion platform assembly and configured to determine a true-gravity zero reference, and a control unit for determining the actual position of elevation frame assembly based upon the sensed motion about said predetermined X, Y, and Z axes and said true-gravity zero reference, and for controlling the azimuth, cross-level and elevation drivers to position the elevation frame assembly in a desired position. Instead of or in addition to the motion platform assembly, the antenna system may include primary and secondary antenna affixed relative to the cross-level frame assembly and a control unit for selecting operation of a selected on of the primary and secondary antennas, determining the actual position of elevation frame assembly based upon the sensed motion about said predetermined X, Y, and Z axes, and for controlling the azimuth, cross-level and elevation drivers to position the selected one of the primary and secondary antennas in a desired position for tracking a communications satellite, Methods of using the three-axis pedestal having motion platform assembly is also described.
摘要:
A pedestal arrangement for stabilization of a RF communication antenna that comprises an antenna group of at least three spatially separated GNSS antennas (Al, A2, A3) for receiving a navigation signal from a satellite transmitter a global navigation satellite system (GNSS). The GNSS antennas have respective outputs for providing GNSS navigation signals to an attitude determining device. A drive means for driving a movable pedestal part of said arrangement about at least one axis, has a drive control input for controlling the drive means for orientation of the communication antenna according to said control input produced by a control device operating on basis of an attitude output received from said attitude determining device. The GNSS antennas are attached in respective locations on or proximal to a circumference of a communication antenna for which said movable pedestal part is adapted to carry, and such that the GNSS antennas stay fixed relative to said movable pedestal part. The present invention also relates to a pedestal arrangement for stabilization of a radio frequency (RF) communication antenna, wherein the arrangement comprises an antenna group of at least two spatially separated GNSS antennas (Al, A2).
摘要:
An antenna for communicating with a satellite from a moving vehicle. The antenna comprises a transmitter for generating a transmission signal, main and sub reflectors, and a waveguide associated with the transmitter for conducting the transmission signal toward the sub reflector. The sub reflector is configured for redirecting the transmission signal toward the main reflector; the main reflector is configured for projecting the redirected transmission signal as an antenna beam toward the satellite.
摘要:
A robust antenna tracking system apparatus (10) is capable of quickly and accurately tracking satellites without the use of a compass under adverse conditions while being subjected to large torque stress and being weatherproof. The apparatus can be attached to a ship or land vehicle and can be used while the vehicle is in motion. Upon the customer choosing a satellite from which to receive signals (202), the invention acquires a satellite by scanning the sky to locate a system labeled primary satellite (204). The identification of the system labeled primary satellite is accomplished by comparing the leading and falling edges of rf-signal pulse (220a), comparing beacon signal transmissions (220b), comparing the relative positioning of other satellites (220c), or determining the angle of elevation of the satellite relative to the horizon (220d). Upon identifying the system labeled primary satellite, the customer chosen satellite is located by calculating its position relative to the system labeled primary satellite (300, 302), and then verifying (306) the customer chosen satellite through on the four identifying means used for the system labeled primary satellite (220a, 220b, 220c and 220d). Satellites are tracked by measuring the increase and decrease in signal strength (308, 310a and 310b) as the antenna is moved a known distance within the satellite's range.