high resistance surface

Abstract

An apparatus for emitting radiation is provided. The apparatus comprises an antenna formed on a substrate, and a high impedance surface (HIS). The HIS has a plurality of cells formed on the substrate that are arranged to form an array that substantially surrounds at least a portion of the antenna. Each cell generally includes a ground plane, first plate, second plate, and an interconnect. The ground plane is formed on the substrate, while the first plate (which is substantially rectangular) is formed over and coupled to the ground plane. The first plate for each cell is also arranged so as to form a first checkered pattern for the array. The second plate (which is substantially rectangular) is formed over and is substantially parallel to the first plate. The first and second plates are also substantially aligned with a central axis that extends generally perpendicular to the first and second plates hand have a interconnect formed therebetween. The second plate for each cell is also arranged so as to form a second checkered pattern for the array.

Description

technical field [0001] The present invention relates generally to radio frequency (RF) antenna structures, and more particularly to high impedance surfaces (HIS). Background technique [0002] For high millimeter-wave frequencies (ie, THz, terahertz radiation), it is difficult to build a radiation structure that satisfies the needs. Typically, the radiation reflects within the package or substrate supporting the antenna, creating surface waves. At the edge of a package or substrate, surface waves can generate parasitic currents that distort the wave pattern. To address this problem, HISs have been used to suppress surface waves and substantially prevent parasitic currents that cause waveform distortion. [0003] Turning to Figures 1 and 2, an example of a conventional HIS 100 can be seen. This HIS 100 mainly consists of an array of cells 102 . Each cell 102 is primarily composed of a ground plane 106 (which typically underlies the entire array), vias 108 and a metal plat...

AI Technical Summary

Problems solved by technology

[0005] However, for HIS100 and 200, there is great difficulty in generating HIS that can be used for high mm-wave frequencies (i.e., terahertz radiation)

The fabrication process (in many cases) will not have fine enough pitch resolution to produce the closely spaced cells of the HIS100 that will function in the desired frequency range, and capacitive coupling for the HIS200 creates further complications because which tends to lower the resonant frequency

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