Switch structure for antennas formed on multilayer ceramic substrates

• US 6,320,547 B1
• Filed: 08/23/2000
• Issued: 11/20/2001
• Est. Priority Date: 08/07/1998
• Status: Active Grant

• Current Assignee: Kung Investment, LLC
• Original Assignee: Sarnoff Corporation (SRI International, Inc.)
• Inventors: Fathy, Aly Eid, Johnson, Henry Charles, Rosen, Arye, Geller, Bernard Dov, Perlow, Stewart Mark
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): NGUYEN, HOANG V
• Application Number:
  US09/644,340
• Time in Patent Office: 454 Days
• Field of Search: 343/700.MS, 343/846, 343/853, 333/262, 333/137, 333/239, 361/760, 361/781, 257/664, 257/728
• US Class Current: 343/700.0MS
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 21/061 Two dimensional planar arrays
• CPC Class Codes: H01Q 9/0414 in a stacked or folded configuration

Abstract

An array antenna includes a first ceramic layer and a second ceramic layer. A metal layer is disposed between the first and second ceramic layers. A plurality of radiating elements are mounted on the first ceramic layer, and a plurality of control circuits are mounted on the second ceramic layer. The control circuits are coupled to the radiating elements through a plurality of conductive vias which feed through the metal layer. The array antenna may also include a switch having a plurality of poles formed in the second ceramic layer and coupled to one of the radiating elements through one or more conductive vias. A plurality of phase delay elements may be coupled at a first end to a signal source and coupled at a second end to the respective plurality of poles of the switch to provide phase-delayed signals. A waveguide may also be formed within the ceramic layers. Conductive vias or coaxial transmission lines may be used to connect elements within the array antenna.

Claims

1. A switch formed in a plurality of ceramic layers stacked on top of a metal layer comprising:

a first electrode having a first portion disposed between a first pair of the ceramic layers and a second portion extending into a cavity formed in the ceramic layers; and

a second electrode having a fixed portion disposed between a second pair of the ceramic layers and a moveable portion extending into and moveable within the cavity to engage the first electrode.

2. The switch of claim 1 further comprising a stimulus pad proximate the first electrode opposite the second electrode, the stimulus pad configured to exert an electrostatic force to pull the moveable portion of the second electrode to engage the first electrode.

3. A method of making a switch in a plurality of ceramic layers stacked on top of a metal layer comprising:

depositing a metal layer;

depositing a first ceramic layer on top of the metal layer;

depositing a stimulus pad on top of the first ceramic layer;

depositing a second ceramic layer on top of the stimulus pad and the first ceramic layer;

depositing a first metal patch and a second metal patch on top of the second ceramic layer, the second metal patch being proximate the stimulus pad;

depositing a third ceramic layer atop the first and second metal patches and the second ceramic layer;

forming a cavity in the third ceramic layer such that a portion of the second metal patch extends into the cavity to define a first electrode;

forming a stand which extends vertically from the first metal patch along a wall of the cavity;

attaching one end of a third metal patch to an end of the stand opposite the first metal patch to define a second electrode, the third metal patch being a hinged portion of the second electrode moveable within the cavity to engage the first electrode.

4. A switch formed in a plurality of ceramic layers, comprising:

a first electrode having a first portion disposed between a first pair of the ceramic layers and a second portion extending into a cavity formed in at least one of the ceramic layers;

a second electrode having a fixed portion disposed between a second pair of the ceramic layers and a moveable portion extending into and moveable within the cavity; and

a stimulus pad proximate the first electrode and opposite the second electrode, the stimulus pad configured to exert an electrostatic force to pull the moveable portion of the second electrode to engage the first electrode.

5. A switch according to claim 4, wherein the movable portion of the second electrode includes a flexible conductor.

6. A switch according to claim 4, further including a third electrode having a first portion disposed on one of the ceramic layers and a second portion extending into a cavity formed in the ceramic layers such that the movable portion of the second electrode is in contact with one of the first and third electrodes responsive to a stimulus applied to the stimulus pad.

7. A switch according to claim 6, wherein:

the plurality of ceramic layers are stacked ceramic layers;

the stimulus pad is disposed between a base layer and a first layer;

the first pair of ceramic layers includes the first layer and a second layer wherein the cavity is formed in the second layer;

the second pair of ceramic layers includes the first layer and the second layer; and

the third electrode is disposed on the second layer, wherein the first and second layers are thinner than the base layer.

8. A switch according to claim 4, wherein:

the plurality of ceramic layers are stacked ceramic layers in an antenna structure having a high-frequency side and a low-frequency side;

the cavity is formed in a ceramic layer on the high frequency side of the antenna structure; and

the switch further comprises control circuitry coupled to the stimulus pad, the control circuitry being mounted on the low-frequency side of the antenna structure and being coupled to the stimulus pad through at least one of the stacked ceramic layers.

9. A switch according to claim 4, wherein the stacked ceramic layers are formed from alumina.

10. A switch according to claim 4, wherein the stacked ceramic layers are formed semi-insulating GaAs.

11. A switched antenna structure formed in a plurality of ceramic layers, the plurality of ceramic layers having a high-frequency side and a low frequency side, the switched antenna structure comprising:

a plurality of antenna elements formed on the high-frequency side of the plurality of ceramic layers;

a plurality of switch elements, each switch element comprising;

a first electrode having a first portion disposed between a first pair of the ceramic layers and a second portion extending into a cavity formed in the ceramic layers;

a second electrode having a fixed portion disposed between a second pair of the ceramic layers and a moveable portion extending into and moveable within the cavity, wherein the first portion of the second electrode is connected to a respective one of the plurality of antennas; and

a stimulus pad proximate the first electrode opposite the second electrode, the stimulus pad configured to exert an electrostatic force to pull the moveable portion of the second electrode to engage the first electrode;

a plurality of waveguides, each waveguide being coupled to provide a signal having a respective phase to a respective one of the first electrodes of the plurality of switch elements.

12. A switched antenna structure formed in a plurality of ceramic layers, the plurality of ceramic layers having a high-frequency side and a low-frequency side, the switched antenna structure comprising:

a plurality of antenna elements formed on the high-frequency side of the plurality of ceramic layers;

a plurality of switch elements, each of the switch elements comprising;

a first electrode having a first portion disposed between a first pair of the ceramic layers and a second portion extending into a cavity formed in at least one of the ceramic layers;

a second electrode having a fixed portion disposed between a second pair of the ceramic layers and a moveable portion extending into and moveable within the cavity;

a third electrode having a first portion disposed on one of the ceramic layers and a second portion extending into a cavity formed in the ceramic layers; and

a stimulus pad proximate the first electrode opposite the second electrode, the stimulus pad configured to exert an electrostatic force to pull the moveable portion of the second electrode to engage one of the the first electrode and the third electrode;

a first plurality of waveguides coupled to provide signals having respective phases to respective ones of the first electrodes of respective ones of the plurality of switches;

a second plurality of waveguides coupled to provide a signal having a respective phase to a respective one of the third electrodes of a respective one of the plurality of switches;

wherein at least one of the plurality of switches is coupled, at its first and third electrodes to respective second electrodes of ones of the switches that are coupled to ones of the first and second plurality of wave guides, and coupled, at its second electrode to at least one of the antennas.