Silent communicator

• US 20050054299A1
• Filed: 09/10/2003
• Published: 03/10/2005
• Est. Priority Date: 09/10/2003
• Status: Abandoned Application

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Hein, Carl, Barnett, Gregory W.
• Application Number:
  US10/659,172
• Publication Number:
  US 20050054299A1
• Time in Patent Office: Days
• US Class Current: 455/67.110
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

A communication method and apparatus includes a transmitter of radio-frequency electromagnetic energy (RF) at a first location. A passive, modulated reflector at a second location reflects incident RF, and is modulated by information to be communicated. The reflected RF thus includes the information. A receiver remote from the reflector receives the reflected, modulated RF and extracts the information therefrom. The receiver may be co-located with the transmitter.

Claims

1. A communication method comprises the steps of:

transmitting radio-frequency energy from a first location;

at a second location remote from said first location, modulating the reflectivity of a passive radio-frequency energy reflector in response to information to be transmitted, whereby modulated radio-frequency energy is reflected by said reflector; and

receiving said modulated radio-frequency energy at a third location remote from said second location.

2. A method according to claim 1, wherein said third location coincides with said first location.

3. A method according to claim 1, wherein said step of modulating includes the step of at least one of modulating the amplitude and phase of said radio-frequency energy.

4. A method according to claim 3, wherein said step of receiving is performed with the aid of knowledge of said at least one of said amplitude and phase.

5. A method according to claim 1, wherein said step of receiving is performed with the aid of knowledge of the modulation.

6. A method according to claim 1, wherein said step of receiving is performed with the aid of mutual synchronization.

7. An apparatus for stealthy information communication, said apparatus comprising:

a transmitter of radio-frequency energy at a first location;

a controllable passive reflector of said radio-frequency energy at a second location, remote from said first location, whereby said reflector reflects reflected radio-frequency energy;

a modulator for controlling said controllable reflector with said information, whereby said reflected radio-frequency energy is modulated; and

a receiver remote from said reflector, and coupled for receiving said modulated radio-frequency energy, and for extracting said information therefrom.

8. An apparatus according to claim 7, wherein the location of said receiver is remote from said first location.

9. An apparatus according to claim 7, wherein said modulator modulates at least one of amplitude and phase of said radio-frequency energy.

10. An apparatus according to claim 7, further comprising synchronization between said modulator and said receiver.