| Current conformal antenna designs often incorporate features which protect surrounding devices from unwanted radiation from the antenna. These antennas include patch antennas and printed dipoles, amongst others. These features, in the form of larger ground planes or absorber-loaded quarter-wave cavities, often are detrimental to the performance of the antenna itself. A relatively new advance in electromagnetic engineering, physics and optics, called the photonic band-gap (PBG) structure and the high impedance ground plane (HIGP) have proven useful in alleviating these effects.; This thesis first highlights the operation of HIGPs and provides computational analysis, using the Finite Element Method (FEM), of a hybrid HIGP/conformal antenna design. Secondly, a novel four-layer design concept for HIGP/antenna structures is presented. This concept uses electric-type or real-source antennas, such as a dipole, placed parallel in close proximity to the HIGP structure separated by a thin layer of low-dielectric material. This design concept helps to better match the antenna by eliminating the phase-reversed reflected wave off of the bottom of the ground plane, thereby allowing an electric-type antenna to be used in close proximity to the ground plane that shields it, and allowing for a lower-profile surface mounted antenna. |
