Multifunctional, Electrically Small, Planar Near-Field Resonant Parasitic Antennas

Planar analogs of previously reported electrically small, electric metamaterial-inspired, near-field resonant parasitic (NFRP) antennas are reported. As with the nonplanar designs, the driven and parasitic elements in each presented case are designed to achieve nearly complete matching of the entire system to a 50-Ω source without any matching network and to yield a high radiation efficiency. By introducing multiple NFRP elements, linearly polarized (LP) dual-band and circularly polarized (CP) planar NFRP antennas are realized. These low-profile designs are validated with experimental results.