Micromechanical microwave switching

• US 5,619,061 A
• Filed: 10/31/1994
• Issued: 04/08/1997
• Est. Priority Date: 07/27/1993
• Status: Expired due to Term

• Current Assignee: Carlton H. Hoel
• Original Assignee: Texas Instruments, Inc.
• Inventors: Goldsmith, Charles, Seymour, David, Kanack, Bradley M., Rhoads, Charles, Norvell, Bill R., Lin, Tsen-Hwang, Pang, Lily Y., Powers, Billy Jr.
• Primary Examiner(s): Prenty, Mark V.
• Application Number:
  US08/332,282
• Time in Patent Office: 890 Days
• Field of Search: 257/528, 257/532, 257/415, 257/419, 257/619, 257/621
• US Class Current: 257/528
• CPC Class Codes: H01G 5/16 using variation of distance between electrodes
• CPC Class Codes: H01G 5/40 Structural combinations of variable capacitors with other electric elements not covered by this subclass, the structure mainly consisting of a capacitor, e.g. RC combinations
• CPC Class Codes: H01H 1/20 Bridging contacts for circuit breakers H01H73/045
• CPC Class Codes: H01H 2001/0042 Bistable switches, i.e. having two stable positions requiring only actuating energy for switching between them, e.g. with snap membrane or by permanent magnet
• CPC Class Codes: H01H 2001/0084 with perpendicular movement of the movable contact relative to the substrate
• CPC Class Codes: H01H 2059/0018 Special provisions for avoiding charge trapping, e.g. insulation layer between actuating electrodes being permanently polarised by charge trapping so that actuating or release voltage is altered
• CPC Class Codes: H01H 2059/0036 Movable armature with higher resonant frequency for faster switching
• CPC Class Codes: H01H 59/0009 making use of micromechanics
• CPC Class Codes: H01H 67/22 Switches without multi-position wipers
• CPC Class Codes: H01P 1/127 Strip line switches
• CPC Class Codes: H01P 1/184 Strip line phase-shifters H01P1/181, H01P1/185, H01P1/19 take precedence
• CPC Class Codes: H01P 5/04 with variable factor of coupling
• CPC Class Codes: H01P 9/00 Delay lines of the waveguide type

Abstract

Micromechanical microwave switches with both ohmic and capacitive coupling of rf lines and integration in multiple throw switches useful in microwave arrays.

Claims

1. An integrated circuit switch, comprising:

(a) a membrane supported over a first conductor on a substrate;

(b) a conductive region on said membrane and connecting to a second conductor on said substrate; and

(c) a pulldown electrode on said substrate and under said membrane,

(d) wherein a voltage greater than a pulldown threshold and applied between said conductive region and said pulldown electrode will pull said membrane down to make a capacitive coupling to said first conductor.

2. The switch of claim 1, further comprising:

(a) a pullup electrode supported over said membrane;

(b) wherein a voltage greater than a pullup threshold and applied between said conductive region and said pullup electrode will pull said membrane up to disrupt any electrical coupling of said membrane to said first conductor when no voltage is applied between said membrane and said pulldown electrode.

3. The switch of claim 2, wherein:

(a) said membrane has two stable states with one stable state with the membrane pulled down and the other stable state with the membrane pulled up.

4. The switch of claim 3, wherein:

(a) said membrane includes a layer of a compressive dielectric.

5. An integrated circuit switch, comprising:

(a) a membrane supported over first and second conductors on a substrate;

(b) a conductive region on said membrane; and

(c) a pulldown electrode on said substrate and under said membrane;

(d) wherein a voltage greater than a threshold and applied between said conductive region and said pulldown electrode will pull said membrane down to electrically couple said first and second conductors.

6. The switch of claim 5, wherein:

(a) said electrically couple is a capacitive couple.

7. The switch of claim 5, wherein:

(a) said electrically couple is an ohmic couple.

8. The switch of claim 5, further comprising:

(a) a pullup electrode supported over said membrane;

(b) wherein a voltage greater than a pullup threshold and applied between said conductive region and said pullup electrode will pull said membrane up to disrupt any electrical coupling of said first and second conductors when no voltage is applied between said membrane and said pulldown electrode.

9. The switch of claim 8, wherein:

(a) said membrane has two stable states with one stable state with the membrane pulled down and the other stable state with the membrane pulled up.

10. An integrated circuit multiple-throw switch, comprising:

(a) a membrane supported over a plurality of output conductors on a substrate;

(b) a conductive region on said membrane and connecting to an input conductor on said substrate; and

(c) a plurality of pulldown electrodes on said substrate and under said membrane;

(d) wherein a voltage greater than a pulldown threshold and applied between said conductive region and one of said plurality of pulldown electrodes will pull said membrane down to make a capacitive coupling to a corresponding one of said plurality of output conductors.

11. An integrated circuit switch comprising:

a dielectric membrane supported over a first conductor on a substrate;

a conductive region on said membrane and connecting to a second conductor on said substrate; and

a pulldown electrode on said substrate and under said membrane,

wherein a voltage greater than a pulldown threshold and applied between said conductive region and said pulldown electrode will pull said membrane down to make an electrical coupling to said first conductor.

12. The switch of claim 11 wherein said coupling is capacitive.

13. The switch of claim 11 wherein said coupling is ohmic.

14. The switch of claim 11 further comprising a pullup electrode supported over said membrane, wherein a voltage greater than a pullup threshold and applied between said conductive region and said pullup electrode will pull said membrane up to disrupt any electrical coupling of said membrane to said first conductor when no voltage is applied between said membrane and said pulldown electrode.

15. The switch of claim 14 wherein said membrane has two stable states with one stable state with the membrane pulled down and the other stable state with the membrane pulled up.

16. The switch of claim 15 wherein said membrane includes a layer of a compressive dielectric.

17. An integrated circuit switch comprising:

a membrane supported over a first conductor on a substrate;

a conductive region on said membrane and connecting to a second conductor on said substrate;

a pulldown electrode on said substrate and under said membrane; and

a pullup electrode supported over said membrane,

wherein a voltage greater than a pulldown threshold and applied between said conductive region and said pulldown electrode will pull said membrane down to make an electrical coupling to said first conductor, and wherein a voltage greater than a pullup threshold and applied between said conductive region and said pullup electrode will pull said membrane up to disrupt any electrical coupling of said membrane to said first conductor when no voltage is applied between said membrane and said pulldown electrode.

18. The switch of claim 17 wherein said membrane has two stable states with one stable state with the membrane pulled down and the other stable state with the membrane pulled up.

19. The switch of claim 18 wherein said membrane includes a layer of a compressive dielectric.