Abstract: A radio frequency reconfigurable lens is provided. In particular, a lens comprising at least two opposed frequency selective surface sheets is provided. A relative phase shift may be imparted to an incident radio frequency wave by varying the distance between at least some of the unit cells of a first of the FSS sheets and adjacent unit cells on a second of the FSS sheets. In order to provide a desired phase taper across the width of a lens, and/or to provide different phase shift amounts, pairs of FSS surfaces having controllable columns or rows can be cascaded together. According to an additional aspect of the present invention, radio frequency waves can be scanned by cascading multiple tunable stages. The present invention also provides a radio frequency shutter.

Abstract: A radio frequency reconfigurable lens is provided. In particular, a lens comprising at least two opposed frequency selective surface sheets is provided. A relative phase shift may be imparted to an incident radio frequency wave by varying the distance between at least some of the unit cells of a first of the FSS sheets and adjacent unit cells on a second of the FSS sheets. In order to provide a desired phase taper across the width of a lens, and/or to provide different phase shift amounts, pairs of FSS surfaces having controllable columns or rows can be cascaded together. According to an additional aspect of the present invention, radio frequency waves can be scanned by cascading multiple tunable stages. The present invention also provides a radio frequency shutter.

Abstract: An antenna structure is provided having one or more spiral antenna arms extending outwardly from a lateral center axis. Each arm is defined by an antenna element disposed in a zig-zag configuration to provide reactive loading to the arm, wherein each arm receives or transmits radio frequency waves about a longitudinal center axis of the arm and the zig-zag element configuration. Thus, the antenna structure has a broader bandwidth than other antennas requiring the same amount of space. The antenna structure also has a substantially omni-directional radiation pattern and a low profile. Each antenna element can be metallisation disposed on a support structure or can be one or more cable conductors. A feed means is provided which can be connected to the elements proximate to the lateral center axis and positioned along or coincident with the longitudinal center axis of one arm or can be connected to one of the elements distal to the lateral center axis.

Abstract: The present invention provides a microstrip antenna that includes a microstrip element with an integral member which is used to establish an electrical connection between the microstrip element and a transmission line. The use of the integral member to establish this electrical connection yields advantages in performance, reliability, and manufacturing, among others, that make the microstrip antenna particularly suitable for mobile applications. The present invention also provides a method of manufacturing such a microstrip antenna.