Tuneable compact antenna design using active EBGs

The use of high impedance electromagnetic bandgap (EBG) structures has been well publicised over many years for improving the input match of antennas, which are placed near metallic ground planes for many applications such as vehicular and aerospace. One of the limiting factors of using EBGs is the bandwidth that is available. The aim of this paper is to illustrate the advantage of using varactor diode devices in a simple EBG structure to tune the reflection phase over a much larger bandwidth than would be available for a passive structure and its application in compact antenna design.