Method and Apparatus for Thermal Management of a Radio Frequency System

• US 20100245179A1
• Filed: 06/10/2009
• Published: 09/30/2010
• Est. Priority Date: 03/24/2009
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Ellsworth, Joseph R., Licciardello, Joseph A., Pereira, Stephen J., Puzella, Angelo M.
• Granted Patent: US 7,859,835 B2
• Time in Patent Office: Days
• US Class Current: 343/702
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2224/73253 Bump and layer connectors
• CPC Class Codes: H01Q 1/02 Arrangements for de-icing; Arrangements for drying-out ; Arrangements for cooling; Arrangements for preventing corrosion
• CPC Class Codes: H01Q 21/061 Two dimensional planar arrays
• CPC Class Codes: H05K 7/20154 Heat dissipaters coupled to components

Abstract

A thermal management system includes an air duct assembly comprising a supply air duct having an air inlet opening, a return air duct having an air exit opening and a plurality of distribution air ducts configured to be in fluid communication with the air inlet opening of the supply air duct and with the air exit opening of the return air duct. A fan is disposed within the air duct assembly to direct air from the air inlet opening of the supply air duct through the supply air duct and out the air exit opening of the return air duct. The fan and supply duct are disposed to direct air over a first surface of a heat sink. A second opposing surface of the heat sink is disposed over and configured to be in thermal contact with a plurality of active circuits disposed on a first surface of a radio frequency (RF) multi-layer printing wiring board (PWB).

Claims

1. An integrated panel array assembly (IPAA) comprising:

(a) an active panel having first and second opposing surfaces, said active panel having a length and a width;

(b) a plurality of active circuits mounted as flip chip circuits on the second surface of said an active panel;

(c) a thermal management system, said thermal management system having a length which is no greater than the length of said active panel and having a width which is no greater than the width of said active panel, said thermal management system comprising;

(1) a heat sink having first and second opposing surfaces with the first surface of said heat sink disposed on and in thermal contact with said the flip chip circuits;

(2) a supply air distribution duct disposed over the second surface of said heat sink;

(3) a fan disposed over said supply air distribution duct, said fan configured to direct air through said supply air distribution duct and toward the second surface of said heat sink;

(4) a return air duct assembly in fluid communication with said supply air distribution duct; and

(5) an exit air ducting segment in fluid communication with said return air duct assembly.

2. The integrated panel assembly of claim 1 further comprising a second heat sink disposed on a first surface of said return air duct assembly such that air traversing said return air duct assembly and exiting said exit air ducting segment passes across at least a portion of said second heat sink.

3. The integrated panel assembly of claim 2 wherein said supply air distribution duct includes an air inlet and said exit air ducting segment is disposed above the air inlet in said supply air distribution duct.

4. The integrated panel assembly of claim 3 further comprising a fan gasket disposed between a first surface of said fan and a first surface of said supply air distribution duct.

5. The integrated panel assembly of claim 1 wherein said return air duct assembly is disposed above said supply air distribution duct assembly.

6. The integrated panel assembly of claim 2 further comprising a heat generating circuit disposed over said second heat sink.

7. The integrated panel assembly of claim 6 wherein said heat generating circuit comprises a DC power converter.

15. The thermal management system of claim 1 further comprising a second heat sink disposed on a first surface of said return air duct assembly such that air traversing said return air duct assembly and exiting said exit air ducting segment passes across at least a portion of said second heat sink.

8. A phased array comprising:

an antenna panel having a plurality of antenna elements disposed on a first surface thereof and having a second opposing surface;

a plurality of integrated panel array assemblies (IPAAs), each of said IPAAs having an integrated thermal management system and each of said IPAAs having an RF signal distribution circuit, a power signal distribution circuit and a logic signal distribution circuit;

a mechanical frame;

an air-manifold system mechanically coupled to said mechanical frame and in fluid communication with each of said plurality of integrated panel array assemblies (IPAAs).

9. The phased array of claim 8 wherein each of said integrated panel array assemblies (IPAAs) comprise a plurality of integrated active panel assemblies.

10. The phased array of claim 9 wherein each of said integrated active panel assemblies (IAPAs) comprises:

an active panel having first and second opposing surfaces;

a plurality of active circuits mounted as flip chip circuits on the second surface of said an active panel;

a heat sink having first and second opposing surfaces with the first surface of said heat sink disposed on and in thermal contact with said the flip chip circuits;

a supply air distribution duct disposed over the second surface of said heat sink;

a fan disposed over said supply air distribution duct, said fan configured to direct air through said supply air distribution duct and toward the second surface of said heat sink;

a return air duct assembly in fluid communication with said supply air distribution duct; and

an exit air ducting segment in fluid communication with said return air duct assembly.

11. The integrated panel assembly of claim 10 wherein said supply air distribution duct includes an air inlet and said exit air ducting segment is disposed above the air inlet in said supply air distribution duct.

12. A thermal management system comprising:

(a) an air duct assembly comprising;

a supply air duct having an air inlet opening;

a return air duct having an air exit opening; and

a plurality of distribution air ducts configured to be in fluid communication with the air inlet opening of the supply air duct and configured to be in communication with the air exit opening of the return air duct;

(c) a heat sink having a first surface configured to contact a plurality of heat generating elements and a second surface having heat spreading elements projecting therefrom;

(b) a fan disposed within the air duct assembly to direct air from the air inlet opening of the supply air duct through the supply air duct and out the air exit opening of the return air duct wherein said fan and supply duct are disposed to direct air over the heat spreading elements projecting from the second surface of said heat sink.

13. The thermal management system of claim 12 wherein said supply air distribution duct includes an air inlet and said exit air ducting segment is disposed above the air inlet in said supply air distribution duct.

14. The thermal management system of claim 12 wherein said return air duct assembly is disposed above said supply air distribution duct assembly.

16. An apparatus, comprising:

an active panel which is thin and generally planar and which has a plurality of active circuits mounted on a first surface thereof as flip chip circuits;

an antenna panel which is disposed on second, opposite surface of said active panel, and which includes a plurality of antenna elements that are each electrically coupled to said active panel; and

a thermal management system which is coupled to said active panel on a side thereof opposite from said antenna section and which is directly thermally coupled to said active circuits.

17. An apparatus according to claim 16, wherein said thermal management system includes a sink which has a surface thereof adjacent said active circuits.

18. An apparatus according to claim 17, wherein said active panel has a plurality of electrical conductors electrically coupled to said plurality of circuits;

wherein said thermal management system further comprises a fan mounting and supply air distribution duct assembly disposed over said heat sink, said distribution duct assembly having a cross-sectional shape corresponding to a truncated triangular shape and which includes an arrangement which is co-operable with said circuit board to hermetically seal said electronic components within said module, said arrangement including a frame sealingly coupled to said circuit board and extending around said electronic components thereon, and including a lid sealingly coupled to a side of said frame opposite from said circuit board; and

wherein said first portion of said module includes a wall portion of said frame that has a plurality of conductors electrically coupled to said interconnection section and includes conductive elements which each electrically couple a respective one of said conductors of said wall portion to a respective one of said conductors of said circuit board.

19. An apparatus according to claim 18, wherein said active panel is provided as a multi-layer printed circuit board, and wherein said first surface of said active panel includes a plurality of connection elements which are each electrically coupled to a respective active circuit disposed thereon.

20. An apparatus according to claim 16, wherein said interconnection section includes a further circuit board, and wherein said first portion includes said module having at an end thereof adjacent said circuit board a plurality of connection elements which are each soldered to said further circuit board.

21. An apparatus according to claim 16, including a plurality of further modules which are each disposed between said interconnection section and said cooling section, which each have electronic components thereon, which each include a first portion operative to electrically couple said electronic components thereon to said interconnection section, and which each include a second portion operative to transfer to said cooling section the heat emitted by said electronic components thereon.

22. An apparatus according to claim 21, wherein said modules are spaced a substantial distance from each other.

23. An apparatus according to claim 16, wherein said electronic components include circuitry which causes said antenna section to function in a multi-beam mode that includes use by said antenna section of at least four separate beams.

24. An apparatus according to claim 23, wherein said electronic components include one of an RF circulator and an RF isolator.

25. An apparatus according to claim 24, wherein said antenna section can both send and receive electromagnetic signals through said antenna elements, and wherein said electronic components include monolithic microwave integrated circuits.

26. An apparatus according to claim 23, wherein said electronic components include a plurality of parts which are each one of an RF circulator and an RF isolator, and which are each associated with a respective one of said beams.

27. An apparatus according to claim 16, including an annular housing which extends between and is coupled to each of said interconnection section and said cooling section, said module being disposed within said housing.

28. An apparatus according to claim 27, wherein said housing is made of a material having a low coefficient of thermal expansion.

29. An apparatus according to claim 16, wherein said interconnection section includes a multi-layer circuit board.

30. An apparatus according to claim 29, wherein said antenna elements of said antenna section are patch antenna elements formed directly on said multi-layer circuit board.

31. An apparatus according to claim 29, wherein said multi-layer circuit board has at least one connector for radio frequency signals, control signals, and power.

32. An apparatus according to claim 16, wherein said cooling section includes a thermally conductive member cooperable with said second portion, and includes a phase change material disposed on a side of said thermally conductive member opposite from said second portion of said module.

33. A method of operating an antenna system which includes a thin and generally planar antenna panel having first and second opposing surface and having a plurality of antenna elements disposed to emit and receive radio frequency signals through a first one of the first and second surfaces and a plurality of active panels electrically coupled to the antenna panel, the method comprising the steps of:

transmitting electrical signals between each of the plurality of active panels and the antenna panel; and

transferring, via a thermal management system, heat emitted by the active circuits on each of the plurality of active panels such that each thermal management system cools a portion of the antenna system such that cooling the antenna system is accomplished via a distributed air cooling process to cool the active panel.

34. A method according to claim 33, wherein transferring, via a thermal management system, heat emitted by the active circuits comprises operating a plurality of fans to move air across a like plurality of active panels such that each of the plurality of fans cools the portion of the antenna system provided of which the active panel is a part.