Two-Port, Dual-Circularly Polarized, Low-Profile Broadside-Radiating Electrically Small Huygens Dipole Antenna

Abstract

A two-port dual-circularly polarized (CP), low-profile broadside-radiating electrically small Huygens dipole antenna is presented that has an advanced feed network and multilayer stacked layout of its electric and magnetic near-field resonant parasitic (NFRP) elements. It radiates left-hand CP (LHCP) or right-hand CP (RHCP) fields at its 1.5 GHz resonance frequency depending on the selected feed port. The measured results, in good agreement with the simulated values, demonstrate that the antenna is electrically small ( ka = 0.94) and low profile ( $0.053\lambda _{0}$ ), relative to the longest wavelength in its −10 dB impedance bandwidth. The port isolation is over 15.6 dB within its 0.99% fractional impedance bandwidth. When port 1 (port 2) is excited, its measured peak realized gain and front-to-back ratio (FTBR) values are, respectively, 1.82 dBi (1.81 dBi) and 4.1 dB (4.5 dB).