Electrically Small, Omnidirectional, Dual-Band, Dual-Polarized Dipole Antenna for Wi-Fi 2.4/5/6E Applications

An electrically small dual-band, dual-polarized omnidirectional dipole antenna is presented. This design combines two dual-band electrically small antenna (ESA) cells arranged in a cross-perpendicular configuration. Each ESA cell incorporates a driven Egyptian axe dipole (EAD), a near-field resonant parasitic (NFRP) grid array, and a pair of parasitic step impedance resonators (SIRs). By the fusion of the SIRs and NFRP grid, which are excited by the same EAD, the electrically small design achieves excellent dual-band performance, covering the entire Wi-Fi 2.4/5/6E bands. The dual-band dual-polarized ESA prototype was optimized, fabricated, and tested. The measured results, which are in good agreement with the simulated values, indicate that the developed ESA (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ka</i> = 0.82 at 2.4 GHz) yields dual-polarized and dual-band characteristics with -10 dB impedance bandwidth of 5.3% and 82.5%, respectively. Additionally, stable realized gain values and omnidirectional radiation patterns are maintained throughout the operational bandwidth. These features make it advantageous over the reported counterparts, and highly suitable for the spaced-limited Wi-Fi devices that work in all official frequency standards.