Phased-array radio frequency receiver

Patent metadata

Field	Value
Publication number	US-11515945-B2
Application number	US-202117322156-A
Country	US
Kind code	B2
Filing date	May 17, 2021
Priority date	Jul 3, 2014
Publication date	Nov 29, 2022
Grant date	Nov 29, 2022

Abstract

A method of RF signal processing comprises receiving an incoming RF signal at each of a plurality of antenna elements that are arranged in a first pattern. The received RF signals from each of the plurality of antenna elements are modulated onto an optical carrier to generate a plurality of modulated signals that each have at least one sideband. The modulated signals are directed along a corresponding plurality of optical channels with outputs arranged in a second pattern corresponding to the first pattern. A composite optical signal is formed using light emanating from the outputs of the plurality of optical channels. Non-spatial information contained in at least one of the received RF signals is extracted from the composite signal.

First claim

What is claimed is:

1. A method of RF signal processing comprising:
receiving, at a plurality of antenna elements, a first RF signal from a first RF source and a second RF signal from a second RF source, each antenna element generating an RF electrical signal in response thereto;
modulating the received RF signals from each of the plurality of antenna elements onto an optical carrier of a first frequency to generate a plurality of modulated signals, each modulated signal having at least one sideband;
directing each of the plurality of modulated signals along a corresponding one of a plurality of optical channels, each of the plurality of optical channels having an output;
transmitting the plurality of modulated signals output from the plurality of optical channels into an interference space to provide interference among the plurality of modulated signals to generate a first interference pattern corresponding to the first RF signal and a second interference pattern corresponding to the second RF signal; and
extracting, from the first interference pattern and the second interference pattern, non-spatial information contained in the first RF signal and the second RF signal, the non-spatial information comprising first data provided by the first RF source and second data provided by the second RF source.

2. The method of claim 1 , wherein extracting nonspatial information contained in the first RF signal further comprises spatial filtering.

3. The method of claim 2 , wherein spatial filtering comprises nulling an optical signal that corresponds to an RF signal.

4. The method of claim 1 , wherein extracting the non-spatial information comprises mixing each of the first interference pattern and the second interference pattern with a reference optical beam of a second frequency, the first frequency and the second frequency differing by a set amount.

5. The method of claim 1 further comprising:
detecting a spatial position of the first RF source and the second RF source from the first interference pattern and the second interference pattern.

6. The method of claim 5 , wherein detecting a spatial position of an RF source further comprises spatial filtering.

7. An RF receiver comprising:
an optical source for providing an optical carrier beam of a first frequency and a reference optical beam of a second frequency, the first frequency and the second frequency differing by a set amount;
a plurality of electro-optic modulators corresponding to a plurality of antenna elements, each modulator configured to modulate the optical carrier beam with a received RF signal of a corresponding antenna element to generate a corresponding modulated optical signal, the plurality of electro-optic modulators thereby configured to generate a plurality of modulated optical signals;
a plurality of optical channels configured to carry the plurality of modulated optical signals, each of the plurality of optical channels having an output to emanate the corresponding modulated optical signal out of the corresponding optical channel;
a composite signal channel, adjacent to the plurality of outputs of the plurality of optical channels, configured to receive the plurality of modulated optical signals, to generate an interference pattern corresponding to the RF signal; and
a detector configured to receive the interference pattern and to extract non-spatial information contained in the RF signal.

8. The RF receiver of claim 7 , further comprising a filter configured to isolate a sideband from at least one modulated optical signal.

9. The RF receiver of claim 8 , wherein the filter is located within the composite signal channel.

10. The RF receiver of claim 7 , wherein the composite signal channel comprises an interference space adjacent the outputs of the plurality of optical channels.

11. The RF receiver of claim 7 , wherein the detector is further configured to extract spatial information corresponding to a spatial position of an RF source of the RF signal.

Assignees

• Phase Sensitive Innovations Inc

Inventors

• Schuetz Chris
• Murakowski Janusz
• Schneider Garrett
• Shi Shouyuan
• Prather Dennis

Classifications

• H01Q3/2676 Primary

  Optically controlled phased array · CPC title

• H04B10/5165 Primary

  Carrier suppressed; Single sideband; Double sideband or vestigial · CPC title

• H04B1/16

  Circuits · CPC title

• H04B10/11

  Arrangements specific to free-space transmission, i.e. transmission through air or vacuum · CPC title

• H04B10/25759 Primary

  Details of the reception of RF signal or the optical conversion before the optical fibre · CPC title