Compact One-Layer Series-Fed Omnidirectional Circularly Polarized Antenna Array

In this paper, a compact omnidirectional circularly polarized antenna array based on one-layer dielectric plate structure is proposed, and the antenna array uses series feed. The dimension of the proposed antenna array is 1.98λ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> × 0.36λ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> × 0.016λ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> (λ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> is the wavelength of the lowest operating frequency in free space). In order to achieve the circularly polarized radiation pattern, the field suppression structure is periodically loaded on both sides of the parallel strip line shorted at ends, which can be equated to a magneto current source. A metal patch is periodically introduced as a current source. The generation of circularly polarized radiation is achieved through the use of the phase difference between the electric and magnetic fields within the dielectric cavity. The simulation of the antenna array shows the 10-dB impedance bandwidth of 1.1% from 8.12 GHz to 8.21 GHz, the 3-dB axial ratio (AR) bandwidth of 1.3% from 8.11 GHz to 8.22 GHz, and the antenna array achieves a maximum peak realized gain of 6.63 dBic.