Increasing RF power output in photonics-fed phased array antenna systems
First Claim
1. A method for delivering a radio frequency (RF) signal to a remote phased array antenna system, comprising:
- using an optical modulator at an RF source location to modulate an optical carrier signal with a source RF signal SRF so as to produce a high power transmit modulated optical carrier (TMOC) signal;
using an optical link comprised of an optical fiber to communicate the high power TMOC signal from the RF source location to an antenna location associated with an RF antenna system, the antenna location remote from the RF source location;
at the antenna location, splitting the high power TMOC into N optical paths to obtain N reduced power TMOC signals, where N is an integer value greater than 1;
in each of the N optical paths, performing a photodetection operation upon the reduced power TMOC signal to obtain N reduced power S′
RF signals;
constructively combining the N reduced power S′
RF signals in an RF power combiner to obtain a high power S′
RF signal;
communicating at least a portion of the high power S′
RF signal to at least one antenna element of said RF antenna system; and
choosing a value of N such that a multiplicity of reduced power S′
RF signals are combined in the combining step, whereby a power level of the high power S′
RF signal exceeds a maximum power handling ability of a photodetector used in each of the N optical paths.
3 Assignments
0 Petitions
Accused Products
Abstract
Delivering a radio frequency (RF) signal to a remote phased array antenna system involves using an optical modulator at an RF source location to modulate a high power optical carrier signal with a source RF signal SRF so as to produce a high power transmit modulated optical carrier (TMOC) signal. An optical link communicates the high power TMOC signal to a remote antenna location, where the high power TMOC is split into N optical paths to obtain N reduced power TMOC signals. In each of the N optical paths, photodetection operations are performed upon the reduced power TMOC signal to obtain N reduced power S′RF signals which are then constructively combined to obtain a high power S′RF signal which is communicated to at least one antenna element.
39 Citations
19 Claims
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1. A method for delivering a radio frequency (RF) signal to a remote phased array antenna system, comprising:
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using an optical modulator at an RF source location to modulate an optical carrier signal with a source RF signal SRF so as to produce a high power transmit modulated optical carrier (TMOC) signal; using an optical link comprised of an optical fiber to communicate the high power TMOC signal from the RF source location to an antenna location associated with an RF antenna system, the antenna location remote from the RF source location; at the antenna location, splitting the high power TMOC into N optical paths to obtain N reduced power TMOC signals, where N is an integer value greater than 1; in each of the N optical paths, performing a photodetection operation upon the reduced power TMOC signal to obtain N reduced power S′
RF signals;constructively combining the N reduced power S′
RF signals in an RF power combiner to obtain a high power S′
RF signal;communicating at least a portion of the high power S′
RF signal to at least one antenna element of said RF antenna system; andchoosing a value of N such that a multiplicity of reduced power S′
RF signals are combined in the combining step, whereby a power level of the high power S′
RF signal exceeds a maximum power handling ability of a photodetector used in each of the N optical paths. - View Dependent Claims (2, 3, 4, 5)
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6. A method for delivering a radio frequency (RF) signal to a remote phased array antenna system, comprising:
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using an optical modulator at an RF source location to modulate an optical carrier signal with a source RF signal SRF so as to produce a high power transmit modulated optical carrier (TMOC) signal; using an optical link comprised of an optical fiber to communicate the high power TMOC signal from the RF source location to an antenna location associated with an RF antenna system, the antenna location remote from the RF source location; at the antenna location, splitting the high power TMOC into N optical paths to obtain N reduced power TMOC signals, where N is an integer value greater than 1; in each of the N optical paths, performing a photodetection operation upon the reduced power TMOC signal to obtain N reduced power S′
RF signals;constructively combining the N reduced power S′
RF signals in an RF power combiner to obtain a high power S′
RF signal;communicating at least a portion of the high power S′
RF signal to at least one antenna element of said RF antenna system; andfurther comprising dynamically varying a phase of the high power S′
RF signal prior to communicating the high power S′
RF signal to the at least one antenna element;wherein the at least one antenna element is one of a plurality of antenna elements comprising an array, and the method further comprises coordinating the phase variation applied to the high power S′
RF signal to facilitate a phased array beam forming operation.
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7. A phased array communication system, comprising:
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an optical modulator at an RF source location which is configured to modulate a an optical carrier signal with a source RF signal SRF so as to produce a high power transmit modulated optical carrier (TMOC) signal; an optical link comprised of an optical fiber configured to communicate the high power TMOC signal from the RF source location to an antenna location associated with an RF antenna system, the antenna location remote from the RF source location; a high power optical power splitter disposed at the antenna location and configured to split the high power TMOC into N optical paths to obtain N reduced power TMOC signals, where N is an integer value greater than 1; wherein each of the N optical paths is comprised of a photodetector configured to produce a reduced power S′
RF signal from the reduced power TMOC signal;a feed waveguide configured for coupling one of the N reduced power TMOC signals to the photodetector; and an optical conversion structure configured to optically convert the reduced power TMOC signal from a less-confined geometry associated with a high power waveguide used in the high power optical power splitter to a more confined geometry associated with the feed waveguide; an RF combiner configured to receive the reduced power S′
RF signal from each of the N optical paths, and constructively combine the N reduced power S′
RF signals to obtain a high power S′
RF signal; andat least one phase control element responsive to a control system and configured to dynamically steer an RF beam produced using the high power S′
RF signal by dynamically controlling a signal phase. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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Specification