Artificial magnetic conductor from a layer of dogbone-shaped conductors over a ground plane

Abstract

Artificial magnetic conductors (AMCs) have received considerable attention because of their unusual reflection property and potential applications at microwave and millimeter wave frequencies. Most AMCs are composed by a periodic conducting pattern based on a unit cell, printed on top of a substrate and backed with a metallic ground plane. This type of surface exhibits a resonance mode which enables the surface acting as an AMC. In this work the reflection property of ground backed AMC layer composed by dogbone shaped conductors is investigated numerically and experimentally in a closed waveguide environment. Compared to other proposed AMC structure in the literature as, the dogbone layer has the advantage that it can have a very subwavelength thickness and it does not require ground pins. The structure is analyzed both inside a waveguide and in free space. Full wave simulations are analyzed in both cases and the results are also compared with the one from an equivalent transmission line (TL) model based on modification of previous papers. Some preliminary results were also shown in. The results show that the phase of reflection coefficient is 0 degree at 6.4GHz. To further verify the result, measurement of reflection coefficient of triple dogbone element inside a Cband waveguide is also conducted. Though in this summary the AMC thickness is 2mm at 6GHz, results show that its thickness can be further reduced.