Transmission line phase shifter

• US 20050134404A1
• Filed: 10/08/2004
• Published: 06/23/2005
• Est. Priority Date: 12/17/2003
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Kajiya, James T.
• Granted Patent: US 7,026,892 B2
• Time in Patent Office: Days
• US Class Current: 333/156
• CPC Class Codes: H01P 1/181 using ferroelectric devices
• CPC Class Codes: H01P 1/184 Strip line phase-shifters H01P1/181, H01P1/185, H01P1/19 take precedence
• CPC Class Codes: H01Q 21/0006 Particular feeding systems
• CPC Class Codes: H01Q 21/08 the units being spaced along or adjacent to a rectilinear path waveguide fed H01Q21/0037
• CPC Class Codes: H01Q 25/004 providing two or four symmetrical beams for Janus application
• CPC Class Codes: H01Q 3/32 by mechanical means
• CPC Class Codes: H01Q 3/36 with variable phase-shifters

Abstract

A transmission line phase shifter ideally suited for use in low-cost, steerable, phased array antennas suitable for use in wireless fidelity (WiFi) and other wireless telecommunication networks, in particular multi-hop ad hoc networks, is disclosed. The transmission line phase shifter includes a wire transmission line, such as a coaxial, stripline, microstrip, or coplanar waveguide (CPW) transmission line. A high-permittivity dielectric element that overlies the signal conductor of the wire transmission line is used to control phase shifting. Phase shifting can be electromechanically controlled by controlling the space between the high-permittivity dielectric element and the signal conductor of the wire transmission line or by electrically controlling the permittivity of the high-permittivity dielectric element.

Claims

1. A transmission line phase shifter comprising:

a signal conductor;

a high-permittivity dielectric element overlying said signal conductor; and

a controller for controlling the interaction of the permittivity of the high-permittivity dielectric element with the signal conductor.

2. A transmission line phase shifter as claimed in claim 1, including a dielectric sheet and wherein said signal conductor is located on a surface of said dielectric sheet.

3. A transmission line phase shifter as claimed in claim 2 wherein said dielectric sheet is a printed circuit board sheet and wherein said signal conductor is created by printing said signal conductor on said printed circuit board.

4. A transmission line phase shifter as claimed in any one of claims 1-3 wherein said high-permittivity dielectric element is formed of a material chosen from the group consisting of Rutile (Titanium Dioxide) and compounds of Rutile containing alkali earth metals.

5. A transmission line phase shifter as claimed in claim 4 wherein said alkali earth metals are chosen from the group consisting of Barium and Strontium.

6. A transmission line phase shifter as claimed in any one of claims 1-3 wherein said controller for controlling the interaction of the permittivity of the high-permittivity dielectric element on said signal conductor includes an electromechanical system for controlling the position of said high-permittivity dielectric element with respect to said signal conductor.

7. A transmission line phase shifter as claimed in claim 6 wherein said high-permittivity dielectric element is a planar layer that includes a high-permittivity dielectric material and wherein said layer is positioned with respect to said signal conductor by moving said layer toward and away from said signal conductor.

8. A transmission line phase shifter as claimed in claim 7 wherein said high-permittivity dielectric layer comprises a supporting layer formed of a dielectric material and a plurality of slugs mounted on said dielectric supporting layer.

9. A transmission line phase shifter as claimed in claim 7 wherein said high-permittivity dielectric layer is a self supporting layer.

10. A transmission line phase shifter as claimed in claim 6 wherein said high-permittivity dielectric element is a cylinder that includes a high-permittivity material and wherein said cylinder is positioned with respect to said signal conduction by rotating said cylinder along an axis offset from the axis of said cylinder.

11. A transmission line phase shifter as claimed in any one of claims 1-3 wherein said high-permittivity dielectric element is formed of a ferroelectric material and wherein said controller for controlling the interaction of the permittivity of the high-permittivity dielectric element on said signal conductor controls the application of electrical energy to said ferroelectric material.