Shaped ground plane for dynamically reconfigurable aperature coupled antenna

• US 20060256027A1
• Filed: 07/20/2006
• Published: 11/16/2006
• Est. Priority Date: 08/27/2003
• Status: Active Grant

• Current Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Rawnick, James J., Brown, Stephen B., Durham, Timothy E.
• Granted Patent: US 7,336,238 B2
• Time in Patent Office: Days
• US Class Current: 343/861
• CPC Class Codes: H01Q 9/0442 with particular tuning means
• CPC Class Codes: H01Q 9/0457 electromagnetically coupled to the feed line

Abstract

Method for controlling an input impedance of an antenna (100). The method can include the steps of coupling RF energy from an input RF transmission line (106) to an antenna radiating element (102) through an aperture (112) defined in a ground plane (110). For example, the aperture (112) can be a slot and the radiating element (102) can be a patch type element. The input impedance can thereafter be controlled by selectively varying a volume or a position of a conductive fluid (128) disposed in a predetermined region between the RF transmission line and the antenna radiating element. The volume of conductive fluid (128) can be automatically varied in response to at least one control signal (132).

Claims

1. A method for controlling an input impedance of an antenna, comprising the steps of:

coupling RF energy from an input RF transmission line to an antenna radiating element through an aperture defined in a ground plane; and

controlling said input impedance by selectively varying at least one dimension of said aperture in response to a control signal.

2. The method according to claim 1 wherein said step of varying said at least one dimension of said aperture further comprises varying at least one of a volume and a position of a conductive fluid.

3. The method according to claim 1 further comprising the step of varying said at least one dimension to maintain an input impedance in a pre-defined range over a selected range of frequencies.

4. The method according to claim 2 further comprising the step of varying at least one of said position and said volume in response to at least one feedback signal provided by a sensor.

5. The method according to claim 1 further comprising the step of forming said aperture as a slot.

6. The method according to claim 5 wherein said step of varying said at least one dimension comprises varying a length of said slot transverse to a length of said RF transmission line.

7. The method according to claim 1 further comprising the step of selecting said radiating element to be a conductive metal patch.

8. The method according to claim 2 further comprising the step of constraining said conductive fluid in a dielectric cavity structure.

9. The method according to claim 2 wherein said conductive fluid is electrically coupled to said ground plane.

10. A method for controlling an input impedance of an antenna, comprising the steps of:

configuring an aperture coupled antenna to have a first input impedance at a first operating frequency;

selectively varying at least one of volume and a position of a conductive fluid disposed in a predetermined region of said aperture coupled antenna between an input RF transmission line and an antenna radiating element to cause a second input impedance at a second operating frequency different from said first operating frequency to be approximately equal to said first input impedance.