Patent ID: 7429961
Filing Date: 2008-09-30
Classification: H01Q

Abstract:
1. Method for fabricating an antenna structure having adjustable radiation characteristics, the method comprising: providing a frequency selective surface including a patterned layer of conducting material having electromagnetic properties that vary as a function of frequency, the frequency selective surface further including a layer of dielectric material having first and second opposing surfaces, the patterned layer of conducting material being disposed on the first surface of the layer of dielectric material, the frequency selective surface further comprising a secondary patterned layer of conducting material applied to the second surface of the layer of dielectric material, wherein the patterned layer of conducting material and secondary patterned layer of conducting material each comprise a similar pattern of conductive elements; positioning an antenna element proximate to the frequency selective surface to promote near field coupling of electromagnetic energy between the antenna element and the patterned layer of conducting material, when the antenna element is operated at a selected frequency; structuring the patterned layer of conducting material to have specific electromagnetic properties at the selected frequency of operation of the antenna element to obtain a predetermined adjustment of the radiation characteristics of the antenna structure, wherein the radiation characteristics of the antenna structure are defined by TE and TM radiation patterns, each having respective electric and magnetic field components; and shifting the patterned layer of conducting material with respect to the secondary patterned layer to provide an offset between the conducting elements on the opposing surfaces of the dielectric material in a direction tangent to one of the opposing surfaces, whereby the amount of offset determines polarization direction for the electric field of the TM radiation pattern.