High-power microwave system employing a phase-locked array of inexpensive commercial magnetrons

• US 20060208672A1
• Filed: 03/18/2005
• Published: 09/21/2006
• Est. Priority Date: 03/18/2005
• Status: Active Grant

• Current Assignee: L-3 Communications Corporation (L3Harris Technologies, Inc.)
• Original Assignee: L-3 Communications Corporation (L3Harris Technologies, Inc.)
• Inventors: Lerma, Albert, Achenbach, Robert Parker
• Granted Patent: US 7,164,234 B2
• Time in Patent Office: Days
• US Class Current: 315/500
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 3/54 Amplifiers using transit-time effect in tubes or semiconductor devices parametric amplifiers H03F7/00; solid state travelling-wave devices H10N70/10
• CPC Class Codes: H03F 3/602 Combinations of several amplifiers
• CPC Class Codes: H05H 1/46 using applied electromagnetic fields, e.g. high frequency or microwave energy H05H1/26 takes precedence

Abstract

A high-power microwave generator employing a plurality of inexpensive commercial magnetron tubes cross-coupled by means of a secondary coupling path between each magnetron output pair, whereby a portion of the output energy from a first magnetron tube is injected into a second magnetron tube and a portion of the output energy from the second magnetron tube is similarly injected into the first magnetron tube. The resulting cross-injection of microwave energies brings the respective magnetron tube pair into a phase-lock sufficiently stable to permit coherent combination of their outputs for many high-power microwave applications, such as directed energy weapon systems. The magnetron phase-locking system requires no external components other than the secondary coupling paths of this invention.

Claims

1. A microwave power generator system comprising:

a plurality of magnetron tubes each having

an anode coupled to an output cavity, and

a primary coupling waveguide having a sidewall disposed to transfer microwave energy from the magnetron output cavity to free space to produce a radiated microwave field; and

secondary cross-coupling means disposed to redirect a portion of the microwave energy from a first magnetron tube output cavity into a second magnetron tube output cavity and to redirect a portion of the microwave energy from the second magnetron tube output cavity into the first magnetron tube output cavity.

2. The system of claim 1 wherein:

the secondary cross-coupling means includes a first reflective element disposed in the microwave field radiated from the first magnetron tube to redirect a portion of the microwave energy from the first magnetron output cavity into the second magnetron output cavity.

3. The system of claim 2 wherein:

the secondary cross-coupling means includes a second reflective element disposed in the microwave field radiated from the second magnetron tube to redirect a portion of the microwave energy from the second magnetron output cavity into the first magnetron output cavity.

4. The system of claim 1 further comprising:

a first sidewall aperture disposed in the sidewall of the primary coupling waveguide of the first magnetron tube;

a second sidewall aperture disposed in the sidewall of the primary coupling waveguide of the second magnetron tube; and

a secondary cross-coupling waveguide disposed to couple the first sidewall aperture to the second sidewall aperture.

5. The system of claim 1 wherein:

the plurality of magnetron tubes includes a plurality of standardized commercial magnetron tubes suitable for microwave oven applications.

6. A directed energy weapon system for projecting microwave energy along a predetermined path, the system comprising:

a plurality of magnetron tubes each having

an anode coupled to an output cavity, and

a primary coupling waveguide having a sidewall disposed to transfer microwave energy from the magnetron output cavity to free space to produce a radiated microwave field; and

secondary cross-coupling means disposed to redirect a portion of the microwave energy from a first magnetron tube output cavity into a second magnetron tube output cavity and to redirect a portion of the microwave energy from the second magnetron tube output cavity into the first magnetron tube output cavity.

7. The system of claim 6 wherein:

the secondary cross-coupling means includes a first reflective element disposed in the microwave field radiated from the first magnetron tube to redirect a portion of the microwave energy from the first magnetron output cavity into the second magnetron output cavity.

8. The system of claim 7 wherein:

the secondary cross-coupling means includes a second reflective element disposed in the microwave field radiated from the second magnetron tube to redirect a portion of the microwave energy from the second magnetron output cavity into the first magnetron output cavity.

9. The system of claim 6 further comprising:

a first sidewall aperture disposed in the sidewall of the primary coupling waveguide of the first magnetron tube;

a second sidewall aperture disposed in the sidewall of the primary coupling waveguide of the second magnetron tube; and

a secondary cross-coupling waveguide disposed to couple the first sidewall aperture to the second sidewall aperture.

10. The system of claim 6 wherein:

the plurality of magnetron tubes includes a plurality of standardized commercial magnetron tubes suitable for microwave oven applications.

11. A microwave power generator system comprising:

a plurality of magnetron tubes each having

an anode coupled to an output cavity, and

a primary coupling waveguide having a sidewall disposed to transfer microwave energy from the magnetron output cavity to free space to produce a radiated microwave field, wherein

the magnetron tube plurality is disposed in an array having a plurality of columns and a plurality of rows; and

secondary row cross-coupling means disposed between a first and a second magnetron tube within a single array column to redirect a portion of the microwave energy from the first magnetron tube output cavity into the second magnetron tube output cavity and to redirect a portion of the microwave energy from the second magnetron tube output cavity into the first magnetron tube output cavity.

12. The system of claim 11 further comprising:

secondary column cross-coupling means disposed between a third and a fourth magnetron tube within a single array row to redirect a portion of the microwave energy from a third magnetron tube output cavity into a fourth magnetron tube output cavity and to redirect a portion of the microwave energy from the fourth magnetron tube output cavity into the third magnetron tube output cavity.

13. The system of claim 12 wherein:

the secondary column cross-coupling means includes

a first reflective element disposed in the microwave field radiated from the third magnetron tube to redirect a portion of the microwave energy from the third magnetron output cavity into the fourth magnetron output cavity.

14. The system of claim 13 wherein:

the secondary column cross-coupling means includes

a second reflective element disposed in the microwave field radiated from the fourth magnetron tube to redirect a portion of the microwave energy from the fourth magnetron output cavity into the third magnetron output cavity.

15. The system of claim 11 wherein:

the secondary row cross-coupling means includes

a first sidewall aperture disposed in the sidewall of the primary coupling waveguide of the first magnetron tube,

a second sidewall aperture disposed in the sidewall of the primary coupling waveguide of the second magnetron tube, and

a secondary cross-coupling waveguide disposed to couple the first sidewall aperture to the second sidewall aperture.

16. The system of claim 11 wherein:

the plurality of magnetron tubes includes a plurality of standardized commercial magnetron tubes suitable for microwave oven applications.

17. A directed energy weapon system for projecting microwave energy along a predetermined path, the system comprising:

a plurality of magnetron tubes each having

an anode coupled to an output cavity, and

a primary coupling waveguide having a sidewall disposed to transfer microwave energy from the magnetron output cavity to free space to produce a radiated microwave field, wherein

the magnetron tube plurality is disposed in an array having a plurality of columns and a plurality of rows; and

secondary row cross-coupling means disposed between a first and a second magnetron tube within a single array column to redirect a portion of the microwave energy from the first magnetron tube output cavity into the second magnetron tube output cavity and to redirect a portion of the microwave energy from the second magnetron tube output cavity into the first magnetron tube output cavity.

18. The system of claim 17 further comprising:

secondary column cross-coupling means disposed between a third and a fourth magnetron tube within a single array row to redirect a portion of the microwave energy from a third magnetron tube output cavity into a fourth magnetron tube output cavity and to redirect a portion of the microwave energy from the fourth magnetron tube output cavity into the third magnetron tube output cavity.

19. The system of claim 18 wherein:

the secondary column cross-coupling means includes

a first reflective element disposed in the microwave field radiated from the third magnetron tube to redirect a portion of the microwave energy from the third magnetron output cavity into the fourth magnetron output cavity.

20. The system of claim 19 wherein:

the secondary column cross-coupling means includes

a second reflective element disposed in the microwave field radiated from the fourth magnetron tube to redirect a portion of the microwave energy from the fourth magnetron output cavity into the third magnetron output cavity.

21. The system of claim 17 wherein:

the secondary row cross-coupling means includes

a first sidewall aperture disposed in the sidewall of the primary coupling waveguide of the first magnetron tube,

a second sidewall aperture disposed in the sidewall of the primary coupling waveguide of the second magnetron tube, and

a secondary cross-coupling waveguide disposed to couple the first sidewall aperture to the second sidewall aperture.

22. The system of claim 17 wherein:

the plurality of magnetron tubes includes a plurality of standardized commercial magnetron tubes suitable for microwave oven applications.