Reflector circuit

• US 6,456,225 B1
• Filed: 01/03/2001
• Issued: 09/24/2002
• Est. Priority Date: 04/25/1998
• Status: Expired due to Term

• 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): Gregory, Bernarr E.
• Application Number:
  US09/674,119
• Time in Patent Office: 629 Days
• Field of Search: 342/5-16, 342/42-51, 342/175, 342/187
• US Class Current: 342/12
• 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, while also providing a frequency selective limiting characteristic. The circuit comprises an antenna for receiving the illuminating radiation and emitting the corresponding output radiation, a delay line providing a frequency selective limiting and signal storage characteristic and an amplifier assembly. 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 are incorporated and are operable to counteract spontaneous oscillation within the circuit.

Claims

1. A reflector circuit for receiving illuminating radiation having components with respective magnitudes, 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 amplified output radiation, the processing means being arranged for providing frequency selective amplification dependent, for each component present in the illuminating radiation, on the respective magnitude of that component.

2. The circuit according to claim 1, wherein the processing means is arranged for providing amplification which selectively and progressively reduces in response to increased magnitude of the components in the illuminating radiation.

3. The circuit according to claim 1, wherein the processing means incorporates at least one of a reflection amplifier and a transmission amplifier for amplifying the portion of the received signal.

4. The circuit according to claim 3, wherein the processing means incorporates gain controlling means for switching the reflection amplifier alternately between a relatively more reflecting state and a relatively less reflecting state, thereby operating to counteract closed-loop oscillation within the circuit.

5. The circuit according to claim 4, wherein the reflection amplifier includes a transistor configured by means of a feedback arrangement to operate within different portions of the transistor'"'"'s current/voltage characteristics to operate in the relatively more reflecting state and the relatively less reflecting state.

6. 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

.

7. 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 storing means incorporating a magnetostatic wave device arranged for providing a frequency selective response.

8. The circuit according to claim 7, wherein the magnetostatic wave device is operative for providing a signal propagation path through an epitaxial yttrium iron garnet (YIG) magnetic film having a thickness in a range of 10 μ

m to 100 μ

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

9. The circuit according to claim 7, wherein the processing means incorporates a reflection amplifier for amplifying the portion of the received signal, and wherein the storing means is connected in a signal path between the reflection amplifier and the antenna assembly.

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

11. Radar chaff including a reflector circuit for receiving illuminating radiation having components with respective magnitudes, 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 amplified output radiation, the processing means being arranged for providing frequency selective amplification dependent, for each component present in the illuminating radiation, on the respective magnitude of that component.