Satellite system calibration in active operational channels
First Claim
1. A communication system, comprising:
- a plurality of analog receive paths and signal processing equipment onboard a satellite;
wherein each analog receive path, of the plurality of analog receive paths, is configured to receive an RF signal via a respective antenna element of an antenna array onboard the satellite, and is configured to condition the received RF signal before providing it to the signal processing equipment downstream of the analog receive paths; and
wherein due to environmental variations, each analog receive path, of the plurality of analog receive paths, causes respective gain and phase deviations to the RF signal received by the analog receive path before the RF signal is provided to the signal processing equipment; and
a calibration subsystem onboard the satellite and configured to inject a calibration signal into each analog receive path, of the plurality of analog receive paths, while the analog receive path is actively being used to receive and condition an RF signal;
wherein the calibration signal, injected into each analog receive path, of the plurality of analog receive paths, has a power level that is below a noise floor of the analog receive path into which the calibration signal is injected;
wherein for each analog receive path, of the plurality of analog receive paths, the calibration subsystem is also configured to extract the calibration signal and compare the extracted calibration signal to the injected calibration signal to thereby determine the respective gain and phase deviations caused by the analog receive path; and
wherein the calibration subsystem is also configured to adjust gain and phase characteristics of one or more of the analog receive paths based on the gain and phase deviations determined for each of the plurality of analog receive paths to thereby compensate for different gain and phase deviations being caused by different ones of the analog receive paths.
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Accused Products
Abstract
Disclosed herein is a system including analog receive paths and analog transmit paths and signal processing equipment onboard a satellite, and methods for use therewith. For each of a plurality of the analog receive paths, a calibration signal is injected therein below a noise floor thereof, while the path is actively used to receive and condition an RF signal, and the calibration signal is extracted from the analog receive path after the signal has traveled through at least a portion of the path. The extracted calibration signal is compared to the injected calibration signal to determine gain and phase deviations caused by the path. Gain and phase characteristics of the analog receive paths are adjusted to compensate for different gain and phase deviations being caused by different paths. Similar techniques are used to compensate for different gain and phase deviations being caused by different analog transmit paths.
38 Citations
29 Claims
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1. A communication system, comprising:
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a plurality of analog receive paths and signal processing equipment onboard a satellite; wherein each analog receive path, of the plurality of analog receive paths, is configured to receive an RF signal via a respective antenna element of an antenna array onboard the satellite, and is configured to condition the received RF signal before providing it to the signal processing equipment downstream of the analog receive paths; and wherein due to environmental variations, each analog receive path, of the plurality of analog receive paths, causes respective gain and phase deviations to the RF signal received by the analog receive path before the RF signal is provided to the signal processing equipment; and a calibration subsystem onboard the satellite and configured to inject a calibration signal into each analog receive path, of the plurality of analog receive paths, while the analog receive path is actively being used to receive and condition an RF signal; wherein the calibration signal, injected into each analog receive path, of the plurality of analog receive paths, has a power level that is below a noise floor of the analog receive path into which the calibration signal is injected; wherein for each analog receive path, of the plurality of analog receive paths, the calibration subsystem is also configured to extract the calibration signal and compare the extracted calibration signal to the injected calibration signal to thereby determine the respective gain and phase deviations caused by the analog receive path; and wherein the calibration subsystem is also configured to adjust gain and phase characteristics of one or more of the analog receive paths based on the gain and phase deviations determined for each of the plurality of analog receive paths to thereby compensate for different gain and phase deviations being caused by different ones of the analog receive paths. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A communication system, comprising:
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signal processing equipment and a plurality of analog transmit paths onboard a satellite; wherein each analog transmit path, of the plurality of analog transmit paths, is configured to receive an RF signal from the signal processing equipment and condition the RF signal before providing it to a respective antenna element of an antenna array onboard the satellite; and wherein due to environmental variations, each analog transmit path, of the plurality of analog transmit paths, causes respective gain and phase deviations to the RF signal travelling through the analog transmit path before the RF signal is provided to the respective antenna element; and a calibration subsystem onboard the satellite and configured to inject a calibration signal into each analog transmit path, of the plurality of analog transmit paths, while the analog transmit path is actively being used to condition and transmit an RF signal; wherein the calibration signal, injected into each analog transmit path, of the plurality of analog transmit paths, has a power level that is below a noise floor of the analog transmit path into which the calibration signal is injected; wherein for each analog transmit path, of the plurality of analog transmit paths, the calibration subsystem is also configured to extract the calibration signal and compare the extracted calibration signal to the injected calibration signal to thereby determine the respective gain and phase deviations caused by the analog transmit path; and wherein the calibration subsystem is also configured to adjust gain and phase characteristics of one or more of the analog transmit paths based on the gain and phase deviations determined for each of the plurality of analog transmit paths to thereby compensate for different gain and phase deviations being caused by different ones of the analog transmit paths. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A method for use with a satellite that includes analog receive paths and signal processing equipment onboard the satellite,
wherein each of the analog receive paths is configured to receive an RF signal via a respective antenna element of an antenna array onboard the satellite, and is configured to condition the received RF signal before providing it to the signal processing equipment; - and
wherein due to environmental variations each of the analog receive paths causes respective gain and phase deviations to the RF signal received by the analog receive path before the RF signal is provided to the signal processing equipment; the method comprising; (a) for each analog receive path, of a plurality of the analog receive paths, (a.1) injecting a calibration signal into the analog receive path while the analog receive path is actively being used to receive and condition an RF signal, wherein the calibration signal is injected into the analog receive path at a power level that is below a noise floor of the analog receive path; (a.2) extracting the calibration signal from the analog receive path after the calibration signal has traveled through at least a portion of the analog receive path; and (a.3) comparing the calibration signal extracted from the analog receive path to the calibration signal injected into the analog receive path to thereby determine gain and phase deviations caused by the analog receive path; and (b) adjusting gain and phase characteristics of one or more of the plurality of analog receive paths, based on the gain and phase deviations determined for each of the plurality of the analog receive paths, to thereby compensate for different gain and phase deviations being caused by different ones of the plurality of analog receive paths. - View Dependent Claims (22, 23, 24, 25)
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26. A method for use with a satellite that includes signal processing equipment and analog transmit paths onboard the satellite,
wherein each analog transmit path, of the plurality of analog transmit paths, is configured to receive an RF signal from the signal processing equipment and condition the RF signal before providing it to a respective antenna element of an antenna array onboard the satellite; - and
wherein due to environmental variations, each analog transmit path, of the plurality of analog transmit paths, causes respective gain and phase deviations to the RF signal travelling through the analog transmit path before the RF signal is provided to the respective antenna element; the method comprising; (a) for each analog transmit path, of a plurality of the analog transmit paths, (a.1) injecting a calibration signal into the analog transmit path while the analog transmit path is actively being used to condition and transmit an RF signal, wherein the calibration signal is injected into the analog transmit path at a power level that is below a noise floor of the analog transmit path; (a.2) extracting the calibration signal from the analog transmit path after the calibration signal has traveled through at least a portion of the analog transmit path; and (a.3) comparing the calibration signal extracted from the analog transmit path to the calibration signal injected into the analog transmit path to thereby determine gain and phase deviations caused by the analog transmit path; and (b) adjusting gain and phase characteristics of one or more of the plurality of analog transmit paths, based on the gain and phase deviations determined for each of the plurality of the analog transmit paths, to thereby compensate for different gain and phase deviations being caused by different ones of the plurality of analog transmit paths. - View Dependent Claims (27, 28, 29)
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Specification