Wideband Conical-Beam Circularly Polarized Microstrip Antenna for Large Ground Plane

Abstract

A wideband conical-beam circularly polarized (CP) microstrip antenna for an electrically large platform is investigated. The antenna structure simply consists of a center-fed patch and eight shorting vias each of which is surrounded by a modified elliptical-ring slot. The θ-polarization of the proposed antenna is provided by the shorting vias and the coaxial probe, while the φ-polarization is generated by the modified elliptical-ring slots. Moreover, the amplitudes of the two orthogonal polarizations can be controlled separately and are less sensitive to the size of the metal platform. By employing the even and odd modes of the elliptical-ring slot, the proposed antenna exhibits a wide impedance bandwidth. A prototype of the antenna is fabricated and mounted on three ground planes, which function as electrically large metal platforms, with the radii of λ 0 , 2λ 0 , and 10λ 0 . The measured results show that the wideband CP antenna with these three ground planes have the 10-dB impedance bandwidths of 19.4%, 19.5% and 19.9%, and the corresponding 3-dB axial ratio (AR) bandwidths of 25.3%, 25.6%, and 24.8%, respectively. A detailed analysis on the radiation characteristics is also carried out for small to extremely large ground plane extensions.

Broadband Dual Circularly Polarized CBand Antennas

“…The wideband behaviour of the antenna in accordance with dimension and position of the ground plane is analysed in [12]. Circularly polarized antenna with conical beam structure for the extended ground plane is analysed in [13] with respect to polarization and size of metal platform. The analysis on effect of change in impedance bandwidth for changing the shape of inverted L strip which extends from ground is done in [14].…”

Circularly-Polarized Shaped Pattern Planar Antenna for Aerial Platforms

“…Circular polarization gets affected due to the reflections from a metallic structure. In 2015, a circularly polarized conical beam antenna was proposed having the capability to be mounted over large ground planes [26]; however, antenna have a deep null and is not designed for airborne surface mount applications. The designed configuration presented in this paper proposed the use of split-ring resonators to avoid circular polarization distortion and provide mounting compatibility with metallic vehicular structures.…”

Circularly Polarized Omnidirectional Antenna with Dipole Core and Diagonally Adjoined Parasitic Braces for ISM Band Applications

“…In [13], four arcs were incorporated to improve circular polarization of a patch antenna. In [14], elliptical-ring slot was deployed surrounding the main patch to improve circular polarization. In [15], a circular patch connected to ground plane by conductive vias achieved wideband CP but low antenna gain.…”

“…In [15], a circular patch connected to ground plane by conductive vias achieved wideband CP but low antenna gain. The antennas in [11][12][13][14][15] required multilayered PCB and shorting vias.…”