An Interdigitated Structure-Based, Electrically Small Dipole Antenna with Enhanced Bandwidth

A wideband, electrically small dipole antenna with stable radiation performance is presented. Inspired by recently reported metasurface antennas, a coax-fed dipole antenna with periodic patches acting as near-field resonant parasitic (NFRP) elements is first developed. It exhibits operating mechanisms identical to those of the metasurface antennas and, thus, realizes a wide bandwidth and stable radiation patterns across it. Introducing interdigitated structures into the NFRP elements, an electrically small version is realized. A 14.4%, -10-dB fractional impedance bandwidth is achieved along with a stable realized gain, ∼ 1.5 dBi, over it. The antenna has potential applications in future wideband space-limited systems