Passive electromagnetic wave duplexer for millimetric antenna

• US 4,574,288 A
• Filed: 08/26/1982
• Issued: 03/04/1986
• Est. Priority Date: 08/28/1981
• Status: Expired due to Fees

• Current Assignee: Thomson-CSF
• Original Assignee: Thomson-CSF
• Inventors: Baril, Michel, Sillard, Gilles
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Ohralik, Karl
• Application Number:
  US06/411,958
• Time in Patent Office: 1,286 Days
• Field of Search: 343/781 P, 343/768, 343/767, 343/781 R, 343/781 CA, 343/909
• US Class Current: 343/781.00P
• CPC Class Codes: H01Q 15/00 Devices for reflection, refraction, diffraction or polarisation of waves radiated from an antenna, e.g. quasi-optical devices variable for purpose of altering directivity H01Q3/00; arrangements of such devices for guiding waves H01P3/20; variable for purpose of modulation H03C7/02
• CPC Class Codes: H01Q 15/14 Reflecting surfaces; Equivalent structures electromagnetic shields H01Q1/526
• CPC Class Codes: H01Q 25/007 using two or more primary active elements in the focal region of a focusing device for operation on different wavebands H01Q5/22

Abstract

A passive duplexer for electromagnetic waves operated within the millimetric wave range. The duplexer comprises a first horn associated with a radar transmitter and having a propagation axis (Δ₁), a plane circular grid inclined at 45° with respect to (Δ₁), and a second horn associated with the radar receiver and having an axis (Δ₂) at right angles to (Δ₁). The grid is formed by a network of resonant slots equipped with at least one diode.

Claims

1. A passive duplexer for electromagnetic waves, within a radar system comprising a transmitter operating in the millimetric range, a receiver operating in the millimetric range, and an antenna fed by said transmitter and also redirecting electromagnetic signals received from a target to said receiver, comprising:

a first horn adapted to be connected to said transmitter and having a propagation axis Δ

₁ ;

a second horn adapted to be connected to said receiver and having a propagation axis Δ

₂ orthogonal to said axis Δ

₁ ; and

plane circular grid means formed by a dielectric disc metallized on one surface thereof for reflecting or passing incident signals depending upon the power level of said incident signals, said grid means being inclined at a 45°

angle with respect to said axes Δ

₁ and Δ

₂, said metallized surface having a network of resonant slots for passing said incident signals each slot including a diode in conducting relation thereacross.

3. A duplexer according to claim 1 or 2, wherein said grid means is wholly transparent to low power electromagnetic signals and wholly reflective to high power signals.

4. A duplexer according to claim 3, wherein each diode is connected to the opposed edges of a corresponding slot.

5. A duplexer according to claim 4, wherein each said resonant slot includes at least one pair of diodes of identical polarity, which are shunt connected anode-to-cathode in one and the same plane.

6. A duplexer according to claim 4, wherein said resonant slots have a rectangular shape corresponding to the polarization of the radar signal which is to be processed.

7. A duplexer acording to claim 4, wherein said resonant slots have an oval form.

8. A duplexer according to claim 4, wherein said resonant slots have a constriction at their centres.

9. A duplexer according to claim 4, wherein said resonant slots are cruciform, each said cruciform slot including four diodes connected anode-to-cathode in pairs.

2. A passive duplexer for electromagnetic waves, within a radar system comprising a transmitter operating in the millimetric range, a receiver operating in the millimetric range, and an antenna fed by said transmitter and also redirecting electromagnetic signals from a target to said receiver, comprising:

a first horn adapted to be connected to said transmitter and having a propagation axis Δ

₁ ;

a second horn adapted to be connected to said receiver and having a propagation axis Δ

₂ orthogonal to said axis Δ

₁ ; and

plane circular grid means, formed by a semiconductor disc metallized on one surface thereof for reflecting or passing incident signals depending upon the power level of said incident signals, said grid means being inclined at a 45°

angle with respect to said axes Δ

₁ and Δ

₂, said metallized surface having a network of resonant slots for passing said incident signals each slot including a diode in conducting relation thereacross.