Reflector circuit

• US 6,369,772 B1
• Filed: 01/03/2001
• Issued: 04/09/2002
• Est. Priority Date: 04/25/1998
• Status: Expired due to Fees

• Current Assignee: Hanger Solutions, LLC (IP Investments Group LLC)
• Original Assignee: Marconi Caswell Limited (Marconi Holdings Company Limited)
• Inventors: Forster, Ian J
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): NGUYEN, HOANG V
• Application Number:
  US09/674,098
• Time in Patent Office: 461 Days
• Field of Search: 343/850, 343/853, 343/865, 455/104, 455/106, 342/51, 342/203
• US Class Current: 343/850
• CPC Class Codes: G01S 13/751 wherein the responder or reflector radiates a coded signal
• CPC Class Codes: G01S 13/767 Responders; Transponders teaching or practice apparatus for gun-aiming or gun-laying using reflecting targets or active targets F41G3/26
• 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
• CPC Class Codes: G01S 13/825 with exchange of information between interrogator and responder
• CPC Class Codes: G01S 7/38 Jamming means, e.g. producing false echoes

Abstract

A reflector circuit is provided which responds to illuminating radiation with corresponding output radiation of increased magnitude relative to the illuminating radiation. The circuit comprises an antenna for receiving the illuminating radiation and emitting corresponding output radiation, a delay line providing a frequency selective limiting and signal storage characteristic and an amplifier assembly incorporating a reflection amplifier for providing signal amplification. The reflection amplifier is capable of providing high gains approaching +30 dB at relatively low current consumption, for example, tens of microamperes. The antenna provides an input signal upon receipt of the illuminating radiation, a portion of which is amplified, frequency selectively filtered, and then stored for a period after which it is emitted as the output radiation from the circuit. Switches may be incorporated and are operable to counteract spontaneous oscillation within the circuit.

Claims

1. A reflector circuit for receiving illuminating radiation and for emitting corresponding amplified output radiation, the circuit comprising:

a) an antenna assembly for receiving the illuminating radiation, and for providing a corresponding received signal; and

b) processing means for amplifying and storing a portion of the received signal for a period of time for use in generating a corresponding output signal for emission from the antenna assembly as the output radiation, the processing means incorporating reflection amplifying means for amplifying the portion of the received signal.

2. The circuit according to claim 1, wherein the processing means incorporates gain controlling means for switching the reflection amplifying means alternately between a relatively more reflecting state and a relatively less reflecting sate, thereby operable to counteract spontaneous closed-loop oscillation within the circuit.

3. The circuit according to claim 2, wherein the reflection amplifying means comprises a reflection amplifier incorporating a transistor configured by means of a feedback arrangement for operating within different portions of the transistor'"'"'s current/voltage characteristics to operate in the relatively more reflecting state and the relatively less reflecting state.

4. The circuit according to claim 2, wherein the processing means employs storing means for delaying signals propagating to and from the reflection amplifying means so that the gain controlling means is provided with sufficient time to periodically reduce gain provided by the reflection amplifying means to counteract the spontaneous oscillation in the circuit.

5. The circuit according to claim 4, wherein the storing means is arranged for storing a signal within it for a period τ

and then output it, and wherein the gain controlling means is arranged for operating at a rate related to an integer number of the period τ

.

6. The circuit according to claim 1, wherein the processing means is operable for providing frequency selective amplification in response to a magnitude of components present in the illuminating radiation.

7. The circuit according to claim 6, wherein the processing means is arranged for providing amplification which progressively reduces in response to increased magnitude of the components in the illuminating radiation.

8. The circuit according to claim 1, wherein the processing means incorporates storing means for storing the portion of the received signal for use in generating the output signal, the storage means being connected in a signal path between the reflection amplifying means and the antenna assembly.

9. The circuit according to claim 8, wherein the storing means incorporates a magnetostatic wave device arranged for storing the portion of the received signal for use in generating the output signal, and for providing the frequency selective response.

10. The circuit according to claim 9, wherein the magnetostatic device provides a signal propagation path through an epitaxial yttrium iron garnet magnetic film having a thickness in a range of 10 μ

m for storing the portion of the received signal and for providing the frequency selective response.

11. The circuit according to claim 8, wherein the processing means incorporates transmission amplifying means and switching means for providing amplification to counteract signal propagation losses occurring in the storing means.

12. The circuit according to claim 8, wherein the processing means incorporates switching means for alternately switching between the portion of the received signal in the processing means for use in generating the output signal, and applying the output signal to the antenna assembly for emission therefrom as the output radiation.

13. The circuit according to claim 12, wherein the switching means is operable for counteracting spontaneous closed-loop oscillation within the circuit.

14. The circuit according to claim 12, wherein the storing means is arranged for storing a signal within it for a period τ

and then output it, and wherein the switching means is arranged for operating at a rate related to an integer number of the period τ

.

15. The circuit according to claim 1, wherein the antenna assembly comprises a first antenna element for receiving the illuminating radiation and a second antenna element for emitting the output radiation, said first and second antenna elements being mutually spatially separate.

16. The circuit according to claim 1, wherein the antenna assembly incorporates at least one of a patch antenna, a bow-tie dipole antenna, and a traveling wave antenna.

17. The circuit according to claim 1, wherein the processing means incorporates modulating means for applying modulation to the portion of the received signal, thereby modulating the amplified output radiation with data.

18. The circuit according to claim 1, wherein the processing means incorporates acoustic wave delaying means incorporating first transducing means for coupling the received signal to excite input acoustic radiation in the delaying means, and for coupling output acoustic radiation from the delaying means to provide the output signal;

and second transducing means for coupling acoustic radiation from the delaying means to provide at least one input signal to the reflection amplifying means for reflective amplification thereat to provide amplified reflected signals to excite acoustic signals in the delaying means for use in generating the output signal.

19. The circuit according to claim 18, wherein the delaying means incorporates at least one absorbing structure for absorbing the acoustic radiation propagating in the delaying means, and at least one reflecting structure for reflecting the acoustic radiation propagating in the delaying means.

20. The circuit according to claim 18, wherein the second transducing means comprises a plurality of transducers, each transducer connected to its own associated reflection amplifier arranged to provide amplification of the acoustic radiation propagating in the delaying means.

21. The circuit according to claim 20, wherein the first transducing means incorporates a chirped interdigitated electrode structure for providing an enhanced transducing frequency response.

22. The circuit according to claim 20, wherein the transducers and their associated amplifiers are arranged for providing amplification over mutually different frequency ranges.

23. The circuit according to claim 20, wherein the delaying means incorporates reflecting means for reflecting the acoustic radiation propagating in the delaying means, the second transducing means being spatially interposed between the reflecting means and the first transducing means and arranged for amplifying acoustic radiation subsequently reflected from the reflecting means.

24. The circuit according to claim 20, wherein each reflection amplifier is arranged to be periodically switched between a relatively less reflecting state and a relatively more reflecting state, thereby counteracting spontaneous oscillation within the circuit.

25. The circuit according to claim 18, wherein the second transducing means is arranged substantially spatially symmetrically about the first transducing means, thereby receiving acoustic energy emitted in more than one direction from the first transducing means.

26. A pseudo passive transponder tag including a reflector circuit for receiving illuminating radiation and for emitting corresponding amplified output radiation, the circuit comprising:

a) an antenna assembly for receiving the illuminating radiation, and for providing a corresponding received signal; and

b) processing means for amplifying and storing a portion of the received signal for a period of time for use in generating a corresponding output signal for emission from the antenna assembly as the output radiation, the processing means incorporating reflection amplifying means for amplifying the portion of the received signal.

27. Radar chaff including a reflector circuit for receiving illuminating radiation and for emitting corresponding amplified output radiation, the circuit comprising:

a) an antenna assembly for receiving the illuminating radiation, and for providing a corresponding received signal; and

b) processing means for amplifying and storing a portion of the received signal for a period of time for use in generating a corresponding output signal for emission from the antenna assembly as the output radiation, the processing means incorporating reflection amplifying means for amplifying the portion of the received signal.

28. A method of providing amplified output radiation in response to receiving illuminating radiation, comprising the steps of:

a) receiving the illuminating radiation and providing a corresponding received signal;

b) amplifying and storing a portion of the received signal for a period of time;

c) generating an output signal from the portion of the received signal after storage;

d) emitting the output signal as the output radiation; and

e) amplifying the portion of the received signal.