Beacon-on-demand radar transponder

• US 7,042,388 B2
• Filed: 07/14/2004
• Issued: 05/09/2006
• Est. Priority Date: 07/15/2003
• Status: Expired due to Fees

• Current Assignee: Farrokh Mohamadi
• Original Assignee: Farrokh Mohamadi
• Inventors: Mohamadi, Farrokh
• Primary Examiner(s): Lobo, Ian J.
• Application Number:
  US10/891,352
• Publication Number:
  US 20050012654A1
• Time in Patent Office: 664 Days
• Field of Search: 342/30, 342/42, 342/44, 342/45, 342/51
• US Class Current: 342/51
• CPC Class Codes: G01S 13/765 with exchange of information between interrogator and responder
• CPC Class Codes: G01S 13/78 discriminating between different kinds of targets, e.g. IFF-radar, i.e. identification of friend or foe G01S13/75, G01S13/79 take precedence

Abstract

A radar transponder is provided that synchronizes the encoding of repeated radar pulses using an envelope detector to detect the envelope of received radar pulse signals. An edge detector detects the pulse edges in the envelope so that code words may be multiplied with the received radar pulse signals synchronously with the detected pulse edges to provide an encoded pulse train that may be transmitted to a radar interrogator.

Claims

1. A radar transponder, comprising:

an amplifier operable to amplify a received radar pulse train to provide an amplified received radar pulse train;

an envelope detector operable to detect the envelope of the amplified received radar pulse train;

an edge detector operable to detect pulse edges in the envelope;

a code generator operable in a first made of operation for the transponder to provide code words synchronously to the detection of the pulse edges by the edge detector; and

a

a multiplier configured to multiply the synchronously provided code words with the amplified received radar pulse train to provide an encoded pulse train signal.

2. The radar transponder of claim 1, further comprising:

at least one antenna operable to transmit the encoded pulse train.

3. The radar transponder of claim 2, wherein the at least one antenna comprises an antenna array.

4. The radar transponder of claim 2, wherein the transponder is configured to include a second mode of operation, the at least one antenna being further operable to transmit the amplified received radar pulse train in the second mode of operation.

5. The radar transponder of claim 1, wherein the edge detector is configured to detect both rising and falling pulse edges.

6. The radar transponder of claim 1, wherein the edge detector is configured to detect only rising pulse edges.

7. The radar transponder of claim 1, thither including a GPS unit, the code words provided by the code generator encoding locational information from the GPS unit.

8. The radar transponder of claim 1, wherein the code generator is configured to provide its code words responsive to a selection signal, the selection signal being driven according to inputs from a user.

9. A method of encoding, comprising:

receiving a train of radar pulses;

envelope detecting the received train of radar pulses to provide an envelope pulse signal;

edge detecting the envelope pulse signal;

generating code words substantially synchronously to the edges detected in the envelope pulse signal; and

multiplying the generated code words with the received train of radar pulses to provide an encoded pulse train.

10. The method of claim 9, further comprising:

transmitting the encoded pulse train.

11. The method of claim 9, wherein the receiving act comprises receiving and amplifying to provide the received radar pulse train.

12. The method of claim 9, wherein the edge detecting act comprises detecting both rising and falling edges.

13. The method of claim 9, wherein the edge detecting act comprises detecting only rising edges.

14. The method of claim 9, further comprising:

providing coordinates from a GPS unit;

wherein the code words are encoded responsive to the coordinates.