Electronically tunable reflector
AssigneeHRL Laboratories, LLC
InventorsDaniel Sievenpiper, Tsung-Yuan Hsu, Shin-Tson Wu, David M. Pepper
Life of this patent
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Abstract
A tuneable impedance surface for steering and/or focusing a radio frequency beam. The tunable surface comprises a ground plane; a plurality of elements disposed a distance from the ground plane, the distance being less than a wavelength of the radio frequency beam; and a capacitor arrangement for controllably varying the capacitance of adjacent top plates, the capacitor arrangement including a dielectric material which locally changes its dielectric constant in response to an external stimulus.
Claims28
A tuneable impedance surface for steering and/or focusing an incident radio frequency beam, the tunable surface comprising:
- (a) a ground plane;
- (b) a plurality of elements spaced from the ground plane by a distance or distances less than a wavelength of the radio frequency beam;
- and
- (b) a capacitor arrangement for controllably varying the capacitance of adjacent elements including a dielectric material which locally changes its dielectric constant in response to an external stimulus.
A method of tuning a high impedance surface for a radio frequency signal comprising:
- arranging a plurality of generally spaced-apart planar conductive surfaces in an array disposed essentially parallel to and spaced from a conductive back plane, the size of each conductive surface being less than a wavelength of the radio frequency signal and the spacing of each conductive surface from the back plane being less than a wavelength of the radio frequency signal;
- and
- varying the capacitance between adjacent conductive surfaces by locally varying a dielectric constant of a dielectric material to thereby tune the impedance of said high impedance surface.
A tunable reflective surface for a radio frequency signal comprising:
- a conductive ground plane;
- a plurality of generally spaced-apart planar conductive surfaces in an array disposed essentially parallel to and spaced from the ground plane, the size of each conductive surface being less than a wavelength of the radio frequency signal and the spacing of each conductive surface from the ground plane being less than a wavelength of the radio frequency signal;
- and
- a material having a locally varying dielectric constant disposed adjacent said plurality of generally spaced-apart planar conductive surfaces and spaced from said ground plane.
A method of tuning a high impedance surface for reflecting a radio frequency signal therefrom, the method including:
- arranging a plurality of generally spaced-apart planar conductive surfaces in an array disposed essentially parallel to and spaced from a conductive back plane, the size of each conductive surface being less than a wavelength of the radio frequency signal and the spacing of each conductive surface from the back plane being less than a wavelength of the radio frequency signal;
- and
- varying the capacitance between adjacent conductive surfaces while the radio frequency signal is being reflected from said high impedance surface by locally varying a dielectric constant of a dielectric material disposed adjacent to said conductive surfaces.
Dependencies are inferred from the claim text.