ANTENNA CALIBRATION METHOD AND APPARATUS
First Claim
1. For use with a system comprising a phase offset device and providing a plurality of phase-shifted signals to a corresponding plurality of system ports, a method for determining phase offsets necessary for a phase offset device to compensate for differences in the system components up to approximately the system ports, the method comprising:
- providing predetermined phase offsets for at least predetermined system ports to the phase offset device;
driving each of the system ports with a signal;
adjusting the provided phase offset for each predetermined system port until a predetermined phase condition is detected for the predetermined system port with respect to a first system port; and
reducing the provided phase offset for a predetermined system port by the predetermined phase condition for that predetermined system port to determine the compensating phase offset for that predetermined system port with respect to the first system port.
3 Assignments
0 Petitions
Accused Products
Abstract
Measurements of frequency and/or phase are taken at the signal ports (S1-S4) of an ISS device (10). These measurements are used to determine phase errors within the ISS device, and phase errors due to the antenna cables (C1-C4). On port, (e.g., S1) is selected as the reference port and then, based on these determined phase errors, offsetting phase errors are determined to correct the phase for the other ports (e.g., S2, S3, S4) with respect to the reference port. The signals at the antenna ports (A1-A4) are then in phase when an omnidirectional antenna pattern is desired from the TCAS antenna array (16). One in embodiment the frequency of the calibration signal is fixed; in another embodiment two different, fixed frequencies are used; and in still another embodiment the frequency is swept to achieve a predetermined measured phase difference.
42 Citations
55 Claims
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1. For use with a system comprising a phase offset device and providing a plurality of phase-shifted signals to a corresponding plurality of system ports, a method for determining phase offsets necessary for a phase offset device to compensate for differences in the system components up to approximately the system ports, the method comprising:
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providing predetermined phase offsets for at least predetermined system ports to the phase offset device; driving each of the system ports with a signal; adjusting the provided phase offset for each predetermined system port until a predetermined phase condition is detected for the predetermined system port with respect to a first system port; and reducing the provided phase offset for a predetermined system port by the predetermined phase condition for that predetermined system port to determine the compensating phase offset for that predetermined system port with respect to the first system port. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A transmitter system with automatic compensation for certain phase differences in the system, the transmitter system comprising:
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an antenna array having a plurality of antennas in a symmetrical arrangement about an axis; a plurality of system ports connected to the plurality of antennas by a corresponding plurality of antenna cables; a corresponding plurality of transmitters to provide output signals to the plurality of system ports; a phase offset device to provide a corresponding plurality of phase-shifted signals to the plurality of transmitters, a plurality of phase detectors, each phase detector being connected between two system ports to measure the phase difference between the two system ports, each system port being connected to at least three phase detectors; and a processor (1) to control the phase shifts provided by the phase offset device, (2) to activate the plurality of transmitters, (3) to receive the measured phase differences from the plurality of phase detectors, (4) to determine compensating phase offsets based upon the measured phase differences to compensate for the phase differences in system components through the system ports, and (5) to provide an omnidirectional antenna pattern from the antenna array by providing the compensating phase offsets to the phase offset device and activating the plurality of transmitters. - View Dependent Claims (9, 10)
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11. For use with a system having an antenna array having a plurality of antennas in a symmetrical arrangement about an axis, a plurality of system ports connected to the plurality of antennas by a corresponding plurality of antenna cables, and a corresponding plurality of transmitters to provide output signals to the plurality of system ports, a method for determining phase offsets necessary to compensate for differences in the antenna cables, the method comprising:
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causing each transmitter of predetermined ones of the plurality of transmitters to drive its corresponding system port with an output signal, the other system ports not being driven; measuring the phase differences between the output signal at the predetermined, driven system port and return signals at predetermined, non-driven system ports; and determining differential phase offsets to compensate for the differences in antenna cables based upon the measured phase differences. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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19. A transmitter system with automatic compensation for certain phase differences in the system, the transmitter system comprising:
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an antenna array having a plurality of antennas in a symmetrical arrangement about an axis; a plurality of system ports connected to the plurality of antennas by a corresponding plurality of antenna cables; a corresponding plurality of transmitters to provide output signals to the plurality of system ports; a phase offset device to provide a corresponding plurality of phase-shifted signals to the plurality of transmitters, a plurality of phase detectors, each phase detector being connected between two system ports to measure the phase difference between the two system ports, each system port being connected to at least three phase detectors; and a processor (1) to control the phase shifts provided by the phase offset device, (2) to activate predetermined ones of the plurality of transmitters, (3) to receive the measured phase differences from the plurality of phase detectors, (4) to determine differential phase offsets based upon the measured phase differences to compensate for the differences in antenna cables, and (5) to provide an omnidirectional antenna pattern from the antenna array by providing the differential phase offsets to the phase offset device and activating the plurality of transmitters. - View Dependent Claims (20)
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21. For use with a system having an antenna array having a plurality of antennas in a symmetrical arrangement about an axis, a plurality of system ports connected to the plurality of antennas by a corresponding plurality of antenna cables, and a corresponding plurality of transmitters to provide output signals to the plurality of system ports, a method for determining phase offsets necessary to compensate for differences in the antenna cables, the method comprising:
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causing each transmitter of predetermined ones of the plurality of transmitters to drive its corresponding system port with an output signal having a first frequency, the other system ports not being driven; measuring the phase differences between the output signal at the predetermined, driven system port and return signals at predetermined, non-driven system ports; causing each transmitter of predetermined ones of the plurality of transmitters to drive its corresponding system port with an output signal having a second frequency;
the second frequency being different than the first frequency, the other system ports not being driven;measuring the phase differences between the output signal at the predetermined, driven system port and return signals at predetermined, non-driven system ports; and determining the differential phase offsets to compensate for the differences in antenna cables based upon the measured phase differences. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
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33. A transmitter system with automatic compensation for certain phase differences in the system, the transmitter system comprising:
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an antenna array having a plurality of antennas in a symmetrical arrangement about an axis; a plurality of system ports connected to the plurality of antennas by a corresponding plurality of antenna cables; a corresponding plurality of transmitters to provide output signals to the plurality of system ports; a phase offset device to provide a corresponding plurality of phase-shifted signals to the plurality of transmitters, a plurality of phase detectors, each phase detector being connected between two system ports to measure the phase difference between the two system ports, each system port being connected to at least three phase detectors; and a processor (1) to control the phase shifts provided by the phase offset device, (2) to control the frequency of transmission, (3) to activate predetermined ones of the plurality of transmitters, (4) to receive the measured phase differences from the plurality of phase detectors, (5) to determine differential phase offsets based upon the measured phase differences at different frequencies to compensate for the differences in antenna cables, and (6) to provide an omnidirectional antenna pattern from the antenna array by providing the differential phase offsets to the phase offset device and activating the plurality of transmitters. - View Dependent Claims (34, 35, 36, 37)
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38. For use with a system having an antenna array having a plurality of antennas in a symmetrical arrangement about an axis, a plurality of system ports connected to the plurality of antennas by a corresponding plurality of antenna cables, and a corresponding plurality of transmitters to provide output signals to the plurality of system ports, a method for determining phase offsets necessary to compensate for differences in the antenna cables, the method comprising:
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causing each transmitter of predetermined ones of the plurality of transmitters to drive its corresponding system port with an output signal, the other system ports not being driven; starting at a first frequency, measuring the phase differences between the output signal at the driven system port and return signals at predetermined, non-driven system ports while changing the frequency in a first manner and, for each of the predetermined, non-driven system ports, marking the frequency at which a first predetermined phase condition is detected for that predetermined, non-driven system port; measuring the phase differences between the output signal at the driven system port and return signals at the predetermined, non-driven system ports while changing the frequency in a second manner and, for each of the predetermined, non-driven system ports, marking the frequency at which a second predetermined phase condition is detected for that predetermined, non-driven system port; and determining differential phase offsets based upon the marked frequencies. - View Dependent Claims (39, 40, 41, 42, 43, 44, 45, 46, 47)
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48. A transmitter system with automatic compensation for certain phase differences in the system, the transmitter system comprising:
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an antenna array having a plurality of antennas in a symmetrical arrangement about an axis; a plurality of system ports connected to the plurality of antennas by a corresponding plurality of antenna cables; a corresponding plurality of transmitters to provide output signals to the plurality of system ports; a phase offset device to provide a corresponding plurality of phase-shifted signals to the plurality of transmitters, a plurality of phase detectors, each phase detector being connected between two system ports to measure the phase difference between the two system ports, each system port being connected to at least three phase detectors; and a processor (1) to control the phase shifts provided by the phase offset device, (2) to control the frequency of transmission, (3) to activate predetermined ones of the plurality of transmitters, (4) to receive the measured phase differences from the plurality of phase detectors, (5) to determine differential phase offsets to compensate for the differences in antenna cables, the differential phase offsets being based upon the frequencies which produced predetermined phase differences, and (6) to provide an omnidirectional antenna pattern from the antenna array by providing the differential phase offsets to the phase offset device and activating the plurality of transmitters. - View Dependent Claims (49, 50, 51, 52, 53)
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54. A symmetrical S-port board for use with an Integrated Surveillance System (ISS), comprising:
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four S-port cable connection points placed uniformly inside the vertices of the board; six phase detectors placed on the board, each phase detector being connected to two of the cable connection points and being placed approximately midway between those two connection points; two of the phase detectors being aligned in a first direction and being on a first side of the board, the board having a first side and a second side; two of the phase detectors being aligned in a second direction, both being on the same side of the board as each other, the same side being a predetermined one of the first side or the second side, the second direction being orthogonal to the first direction; one of the phase detectors being aligned in a first diagonal direction and being on a first predetermined side of the board, the first diagonal direction being approximately midway between the first direction and the second direction, the first predetermined side being a predetermined one of the first side or the second side; and one of the phase detectors being aligned in a second diagonal direction and being on a second predetermined side, the second diagonal direction being orthogonal to the first diagonal direction, the phase detector in the first diagonal direction being on a second predetermined side of the board, the second predetermined side being opposite to the first predetermined side. - View Dependent Claims (55)
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Specification