High-selectivity electromagnetic bandgap device and antenna system

[0027] EBG materials display a reflection phase versus frequency such as that illustrated in FIG. 4. The center frequency of operation is defined as that frequency where the reflection phase is zero. This point on the frequency response curve is very unique. A consequence of zero-phase reflection is that the electric field is not flipped in polarity as is the case for all other electrical conductors (which may be considered perfect electrical conductors (PECs)), but is in fact reflected without a phase shift. This is a unique property that is provided by the operation of these resonant surfaces. In practice, the bandwidth of operation is defined as the frequency range where the reflection phase is between −90 degrees and 90 degrees.

[0028] With this unique property, antennas can be placed proximate (on or near) these surfaces without experiencing the short-circuiting effects associated with PEC ground planes. As the operating frequency with which the antenna is being driven leaves the