METHOD AND APPARATUS FOR COHERENT ANALOG RF PHOTONIC TRANSMISSION
First Claim
Patent Images
1. A signal transmission system, comprising:
- a phase modulator which modulates a first portion of a light beam with a RF or microwave input signal to produce a phase modulated optical signal;
the first portion of the light beam having a first polarization state;
the first portion of the light beam being transmitted to a receiver along with a second portion of the light beam;
the second portion of the light beam having a second polarization state being orthogonal to the first polarization state; and
a receiver which aligns the polarization states of the beam portions and mixes incoming the first and the second portions of the light beam producing output mixed beams that are detected by a set of photodiodes followed by a digital signal processing (DSP) unit;
the DSP unit outputting an output signal for further processing or display.
1 Assignment
0 Petitions
Accused Products
Abstract
A system for high fidelity analog RF photonic communications is disclosed wherein linear phase modulation and linear coherent demodulation is included. A single optical beam with a phase-modulated signal optical carrier combined with an orthogonally polarized reference unmodulated optical carrier is transmitted simultaneously. At the receiver, the polarization of the reference carrier is transform to match that of the signal followed by coherent detection. An in-phase and quadrature-phase component of the homodyne signal is generated where they are digitized and processed to recover the original RF signal.
126 Citations
20 Claims
-
1. A signal transmission system, comprising:
-
a phase modulator which modulates a first portion of a light beam with a RF or microwave input signal to produce a phase modulated optical signal;
the first portion of the light beam having a first polarization state;the first portion of the light beam being transmitted to a receiver along with a second portion of the light beam;
the second portion of the light beam having a second polarization state being orthogonal to the first polarization state; anda receiver which aligns the polarization states of the beam portions and mixes incoming the first and the second portions of the light beam producing output mixed beams that are detected by a set of photodiodes followed by a digital signal processing (DSP) unit;
the DSP unit outputting an output signal for further processing or display. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
-
-
15. A method of a RF or microwave photonic transmission, comprising:
-
phase modulating a first portion of a light beam with the RF or microwave input signal to produce a phase modulated optical signal;
the first portion of the light beam having a first polarization state;transmitting the first portion of the light beam to a receiver along with a second portion of the light beam;
the second portion of the light beam having a second polarization state being orthogonal to the first polarization state;aligning the polarization states of the beam portions at the receiver side; mixing the first and the second portions of the light beam producing output mixed beams that are detected by a set of photodiodes; and processing electrical signals from the photodiodes in a digital signal processing (DSP) unit;
the DSP unit outputting an output signal for further processing or display. - View Dependent Claims (16, 17, 18, 19, 20)
-
Specification