Phase shift device using voltage-controllable dielectrics

Claim 2

An RF phase shift device, comprising: first and second spaced groundplanes; a conductive housing, said housing comprising said first and second groundplanes and first and second sidewalls extending generally perpendicularly to said groundplanes; first and second spaced conductors disposed between said groundplanes, said conductors being separated by a gap; a dielectric material disposed in said gap, said material characterized by a dielectric constant which varies in value when a voltage is applied to said dielectric material; means for applying a control signal to said dielectric material to set the value of the dielectric constant at a predetermined value in order to provide a desired phase delay region through said device; means for exciting said first and second conductors by an RF signal to provide an anti-phase signal in said phase delay region; and wherein said groundplanes, said conductors and said dielectric material comprise a suspended stripline transmission line in said region, and wherein said second conductor tapers to a greater width on each side of said region to form a microstrip groundplane of a microstrip-to-balanced stripline transition.

Claim 3

The device of claim 1 wherein said means for applying a control signal comprises means for applying a variable electric field across said first and second conductors, said dielectric material having the property that its dielectric constant is dependent upon the magnitude of said electric field.

Claim 4

The device of claim 1, wherein said first and second conductors are arranged in a parallel, width-coupled relationship.

Claim 5

The device of claim 1 wherein said device provides a 360 phase shift range.

Claim 6

The device of claim 1 wherein said dielectric material comprises a composition of BaSrTiO 3 .

Claim 7

The device of claim 1 wherein said means for applying a control signal comprises means for applying a bias dc electric field across said dielectric material.

Claim 8

The device of claim 6 wherein said means for applying a bias dc electric field comprises means for applying a voltage between said first and second conductors.

Claim 9

The device of claim 7 wherein said dielectric material is disposed in said gap within a phase shifting region defined along a section of said first and second conductors, and said means for applying a voltage comprises a dc blocking gap defined in said first conductor on either side of said region, a variable voltage source, and means for electrically connecting said first and second conductors in said region to said voltage source.

Claim 10

The device of claim 8 wherein said electrically connecting means comprises a low pass filter means.

Claim 11

The device of claim 1 further comprising first and second coaxial connectors connected to said respective transitions.

Claim 12

A true-time-delay device for RF signals, comprising: first and second spaced groundplanes; a conductive housing, said housing comprising said first and second groundplanes and first and second sidewalls extending generally perpendicularly to said groundplanes; first and second spaced conductors disposed between said groundplanes, said conductors separated by a gap; dielectric material disposed in said gap along a time delay region extending along a section of said conductors, said material characterized by a variable relative dielectric constant; means for applying a control signal to said dielectric material to set said dielectric constant at a desired value in order to provide a desired time delay to RF signals propagating along a transmission line defined by said conductors in said time delay region; means for exciting said first and second conductors by said RF signals to provide an anti-phase signal in said time delay region; wherein said groundplanes, said conductors and said dielectric material comprise a suspended stripline transmission line in said region, and wherein said second conductor tapers to a greater width on each side of said region to form a microstrip groundplane of a microstrip-to-balanced stripline transition.

Claim 13

A true-time-delay device for RF signals, comprising: first and second spaced groundplanes; a conductive housing, said housing comprising said first and second groundplanes and first and second sidewalls extending generally perpendicularly to said groundplanes; first and second spaced conductors disposed between said groundplanes, said conductors separated by a gap; dielectric material disposed in said gap along a time delay region extending along a section of said conductors, said material characterized by a variable relative dielectric constant; means for applying a control signal to said dielectric material to set said dielectric constant at a desired value in order to provide a desired time delay to RF signals propagating along a transmission line defined by said conductors in said time delay region; means for exciting said first and second conductors by said RF signals to provide an anti-phase signal in said time delay region; wherein said groundplanes, said conductors and said dielectric material comprise a suspended stripline transmission line in said region, and wherein said second conductor tapers to a greater width on each side of said region to form a microstrip groundplane of a microstrip-to-balanced stripline transition.

Claim 14

The device of claim 11 wherein said first and second conductors are arranged in a parallel, width-coupled relationship.

Claim 15

The device of claim 11 wherein said dielectric material comprises a composition of BaSrTiO3.

Claim 16

The device of claim 11 wherein said means for applying a control signal comprises means for applying a variable electric field across said first and second conductors, said dielectric material having the property that its dielectric constant is dependent upon the magnitude of said electric field.