Bandwidth enhancement of the omni‐directional and circularly‐polarized EZR‐MZR antenna

Abstract

As electric and magnetic dipoles with inherent 90 phase difference (PD) can be easily realized by forming a circular array of the epsilon-zero resonance and mu-zero resonance (EZR-MZR) resonators, high design efficiency can be expected for lowprofile, omni-directional and circularly polarized (CP) antenna designing. However, high Q factor of the EZR-MZR resonator makes narrow bandwidth. This research is dedicated to enhance the bandwidth. Low Q factor and multi-resonances techniques are utilized to enhance the impedance bandwidth. While polarization compensation technique is applied to improve the axial ratio (AR) bandwidth by tuning the amplitudes and PD of the orthogonal vectors. The proposed antenna obtains a À 10 dB impedance band of 1.370 to 1.690 GHz (20.91% at 1.530 GHz) and a 3 dB axial ratio (AR) band of 1.260 to 1.580 GHz (22.53% at 1.42 GHz). The diameter and profile of the proposed antenna are 0.402 λ and 0.082 λ, respectively.

A High-Power Sandwiched Omnidirectional Circularly Polarized Antenna for GNSS Systems

“…The phase difference in [6] can be implemented using a top plane with extending stubs and a bottom plane that is identical to the top plane but with a mirror. As demonstrated in [7], the phase difference is caused by the vertically suspended pins that guide vertical polarization and the horizontal parasitic strips of the antenna that guide horizontal polarization . Waveguide-based arrays feature high gain, low dielectric losses, and high-power handling capacity.…”

“…To guarantee CP radiation over a large spatial coverage, the AR should maintain typically a value below 3dB over wide azimuth and elevation angles. Therefore, omnidirectional CP antennas are typically used to cover 360º in azimuth [2]- [7], [11]. However, quite a few reported designs as in [3], [4] and [6] have confirmed their small AR across elevation coverage angles of 70º in [3], 40º in [4] and 90º in [6] classifying them as the AR half power beam widths (ARHPBWs).…”