Antennovation and the Pennsylvania State University propose to develop novel new electromagnetic bandgap (EBG) materials in conjunction with miniaturized broadband antennas for use in man-portable antenna applications. The proposed antenna/EBG system will be designed to be low-profile, compact, and light-weight for helmet-mounted antennas and/or other body-worn applications. The frequency range of 250 MHz to 2.5 GHz will be targeted for operation. Within this range both narrowband tunable and broadband designs will be investigated. The EBG materials will be composed of reactively-loaded planar metallic frequency selective surfaces (FSS) mounted on top of thin metallic backed dielectric substrates. The placement of loads and the surface geometry of the EBG will be optimized via a genetic algorithm (GA) for best performance. This Phase I program will also investigate the use of novel substrate materials such as high-k dielectrics and magnetically loaded substrates for use in achieving ultra-thin and broadband EBG designs at low frequencies. Miniaturized antenna designs will also be developed for use in conjunction with the optimized EBG surfaces towards a goal of providing a complete integrated system that is reduced in size and weight while possessing a high radiation efficiency as well as a low specific absorption rate (SAR).