Multi-functional, electrically small, near field resonant parasitic antennas and their applications

We have developed a variety of electrically small, near-field resonant parasitic (NFRP) antennas. Their NFRP elements are based on different types of metamaterial unit cells and both electric and magnetic couplings between the driven and NFRP elements. High radiation efficiencies and nearly complete matching to the source is achieved with no external matching circuit. Passive and active metamaterial unit cells have been investigated. Multi-functional systems based on a single driven element and on multiple NFRP elements have been reported. Both low profile and conformal versions have been demonstrated. Electrically small antenna applications, including power harvesting, have been explored. Examples of these different classes of small antenna systems and their performance characteristics will be presented.