Phase tracking multichannel link
First Claim
1. A phase tracking multichannel apparatus, comprising:
- a plurality of RF channels wherein each of said RF channels has a phase separation relative to each adjacent RF channel, and an output coupled to each of said RF channels for applying an RF output signal;
a plurality of optical transmitters, each of said optical transmitters having an input for receiving a corresponding RF output signal and an output for applying an optical output signal modulated on an optical carrier, said optical output signal having substantially the same phase as said received RF output signal;
a multiplexer having an input for receiving each of said optical output signals and an output for applying a multiplexed optical output signal having multiple-phase RF components with substantially the same phase separation as between corresponding said RF output signals;
a common optical link having an input for receiving the multiplexed optical output signal and an output for applying the multiplexed optical output signal, said common optical link substantially maintaining the phase separation between corresponding optical signals at said common optical link output as received at said common optical link input; and
an optical signal receiving system having an input for receiving the multiplexed optical output signal.
0 Assignments
0 Petitions
Accused Products
Abstract
A phase tracking multichannel apparatus includes a plurality of optical transmitters, an optical multiplexer, a common optical link, and a user electronics. RF signals having different phases are received and are output on separate RF channels, each of which is coupled to an optical transmitter. RF-modulated optical output signals are then output to the optical multiplexer to produce a multiplexed output signal. The multiplexed signal is applied to a common optical link that at its output substantially maintains the phase separation of RF modulation components on optical carriers as received at its input. The optical output of the common optical link is then applied to an optical signal receiving system, such as an optical demultiplexer and a plurality of photodetectors. By multiplexing all of the optical signals onto the common optical fiber, all signals transmit the same path and, therefore, have the same time and phase delay. The phase tracking is preserved because all of the signals experience the same optical or expansive properties of the common optical fiber. A typical use would be to transmit multiple RF signals from an antenna array to a remote RF phase measuring receiver, such as a RF direction finding system.
-
Citations
34 Claims
-
1. A phase tracking multichannel apparatus, comprising:
-
a plurality of RF channels wherein each of said RF channels has a phase separation relative to each adjacent RF channel, and an output coupled to each of said RF channels for applying an RF output signal;
a plurality of optical transmitters, each of said optical transmitters having an input for receiving a corresponding RF output signal and an output for applying an optical output signal modulated on an optical carrier, said optical output signal having substantially the same phase as said received RF output signal;
a multiplexer having an input for receiving each of said optical output signals and an output for applying a multiplexed optical output signal having multiple-phase RF components with substantially the same phase separation as between corresponding said RF output signals;
a common optical link having an input for receiving the multiplexed optical output signal and an output for applying the multiplexed optical output signal, said common optical link substantially maintaining the phase separation between corresponding optical signals at said common optical link output as received at said common optical link input; and
an optical signal receiving system having an input for receiving the multiplexed optical output signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A phase tracking multichannel apparatus, comprising:
-
a plurality of RF channels wherein each of said RF channels has a phase separation relative to each adjacent RF channel, and an output coupled to each of said RF channels for applying an RF output signal;
a plurality of fixed output light sources, each of said fixed output light sources having an output for applying an optical carrier;
a plurality of modulators, wherein each said modulator includes a first input for receiving a corresponding optical carrier, a second input for receiving a corresponding RF output signal, a third input for receiving a bias control signal, and an output for applying an RF modulated optical output signal;
a plurality of fiber couplers, each said fiber coupler including an input for receiving one of said RF modulated optical output signals, a first output for applying an initial fiber coupler output signal, and a second output for applying a bias-adjusted optical modulator output signal;
a plurality of monitor photodetectors, each said monitor photodetector including an input for receiving a corresponding fiber coupler output signal and an output for applying a monitor photodetector output control signal;
a plurality of bias control circuits, each said bias control circuit including an input for receiving a corresponding monitor photodetector output control signal and an output for applying a bias control signal at said third input of a corresponding optical modulator and thereby bias-adjust each said fiber coupler second output;
a multiplexer having an input for receiving each of said modulator output signals and an output for applying a multiplexed optical output signal having multiple RF modulation components with substantially the same phase separation as between corresponding said RF output signals;
a common optical link having an input for receiving the multiplexed optical output signal and an output for applying the multiplexed optical output signal, said common optical link substantially maintaining the phase separation between RF modulation components on the multiplexed optical signal at said common optical link output as received at said common optical link input; and
an optical signal receiving system having an input for receiving the multiplexed optical output signal. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
-
-
21. A phase tracking multichannel apparatus, comprising:
-
a plurality of RF channels wherein each of said RF channels has a phase separation relative to each adjacent RF channel, and an output coupled to each of said RF channels for applying an RF output signal;
a plurality of fixed output light sources, each of said fixed output light sources having an output for applying an optical carrier;
a plurality of modulators, wherein each said modulator includes a first input for receiving a corresponding optical carrier, a second input for receiving a corresponding RF output signal, and an output for applying an RF modulated optical output signal;
a multiplexer having an input for receiving each of said RF modulated optical output signals and an output for applying a multiplexed optical output signal having multiple RF modulation components with substantially the same phase separation as between corresponding said RF output signals;
a common optical link having an input for receiving the multiplexed optical output signal and an output for applying the multiplexed optical output signal, said common optical link substantially maintaining the phase separation between RF modulation components at said common optical link output as received at said common optical link input; and
an optical signal receiving system having an input for receiving the multiplexed optical output signal. - View Dependent Claims (22, 23, 24, 25)
-
-
26. A method for processing an RF signal, comprising the steps of:
-
receiving a plurality of RF output signals having a relative phase separation therebetween;
modulating each of said plurality of RF output signals upon a plurality of optical carriers to form a plurality of modulated optical output signals;
multiplexing said plurality of RF modulated optical output signals to form a multiplexed optical output signal having multiple RF modulation components with substantially the same phase separation as between corresponding said RF output signals;
transmitting said multiplexed optical output signal in a common optical link, said common optical link substantially maintaining the phase separation between RF modulation components on optical carriers at said common optical link output as received at said common optical link input; and
receiving said multiplexed optical output signal in a user electronics. - View Dependent Claims (27, 28, 29, 30, 31, 32, 33, 34)
-
Specification