Metamaterial Based Patch Antennas And Adaptive Rectifying Circuits For High Power Rectenna Applications

The efforts of this project considered two technological aspects of rectennas systems. One technology that was emphasized power-adaptive- rectifying circuits (PARCs). If a rectenna system is to be integrated into an autonomous vehicle system and fed by a stationary microwave source, the electromagnetic power incident on the rectenna will vary with the distance between - the source and the rectenna. Consequently, the output power from the rectenna could vary dramatically with small changes in the location of the rectenna system. To mitigate these input power effects, we considered a prototype PARC design at 1MHz and a corresponding RF PARC design at 2.45 GHz in the ISM band. As proposed, several power adaptive rectifying circuits were designed, built, and tested. Several metamaterial-based electrically small antennas were also considered during the project duration. These efforts included an integrated antenna- artificial magnetic conductor (AMC) system and a metamaterial-based efficient electrically small dipole antenna. An optimal design of a printed dipole antenna integrated with an AMC block having no ground plane was achieved. An efficient electrically small antenna was achieved by surrounding a center-fed dipole antenna with an ENG (epsilon negative) metamaterial spherical shell and a coax-fed monopole antenna with an ENG metamaterial hemispherical shell.