Pin‐loaded circularly‐polarised patch antenna with sharpened gain roll‐off rate and widened 3‐dB axial ratio beamwidth

Abstract

A circularly‐polarised patch antenna with the loading of shorting pins is proposed in this study to sharpen the gain roll‐off shape and widen the 3‐dB axial ratio beamwidth (ARBW). First of all, it is theoretically revealed that when the electrical size of a circular patch radiator is appropriately constituted, the radiation gain at the horizon can be significantly suppressed and the axial ratio can be maintained below 3 dB over a wide angular range. By introducing a set of metallic pins, which short the patch in a circular contour, the resonant frequency of the antenna will be increased. In this way, the patch radius with respect to wavelength can be freely chosen, so that sharp gain roll‐off rate and wide ARBW can be simultaneously achieved. After the extensive analysis is executed, two circular patch antennas with and without loading of shorting pins are designed, fabricated and tested for comparison. Simulated and measured results show that the gain roll‐off is enhanced up to near 20 dB and 3‐dB ARBW is extended to around 140° so as to effectively reduce the undesired multipath interference as highly demanded in the application of global navigation satellite system.

3-D-Printed Dielectric Lens With Cone-Shaped Cavity for Axial Ratio Beamwidth Enhancement of Circularly Polarized Patch Antenna

“…Firstly, the proposed antenna shows the widest AR bandwidth. In the item of 3-dB ARBW, the proposed antenna shows better performance than the antennas in [1], [6], [15] and [17]. Compared with [10] and [22], the peak gain of the proposed design is higher.…”

Two-Pair Slots Inserted CP Patch Antenna for Wide Axial Ratio Beamwidth

“…In [18], the beamwidth of CP antenna is presented as function of mutual coupled field between slotted structures. The techniques like shorted post [19], shorted plate [20], and SIW based approach [21] have been preferred to enrich the beamwidth performance of the CP antenna. Antennas on a suspended substrate [22] and an extended length of the dielectric substrate [23] have been used to implement wide beamwidth CP antenna.…”

Compact Dual-Band Circularly Polarized Patch Antenna With Wide 3-Db Axial Ratio Beamwidth for Beidou Applications

“…Generally speaking, a wide ARBW can be achieved by helix antennas [4,5], modified turnstile antennas [6], and microstrip antennas [7][8][9][10][11][12][13][14]. Compared with helix and turnstile antennas, microstrip antennas are more preferred for the advantages of low-profile, light weight, and compact structure.…”

“…However, 3-dB ARBWs of conventional CP microstrip antennas (CPMAs) are narrow. In the past, numerous methods were proposed to widen the 3-dB ARBW of CPMAs, such as adopting 3-D ground planes [7][8][9], loading additional radiation elements [10,11], utilizing the aperture area of antennas [12][13][14], and spacing two pairs of parallel dipoles in a square contour [3]. However, the CP antennas using 3-D ground planes [7][8][9] and additional radiation elements [10,11] suffer from high profile, and their complex in geometry may lead to difficulty in fabrication.…”

“…In [12], a suspended structure with reduced effective permittivity was proposed for determining the radiating area, but the performance of the antenna was very sensitive to the error in installation of suspended height. In [13,14], pin-loaded technique was utilized to present a wide 3 dB ARBW. However, the structures were not suitable for electrically small antennas, and the ARBWs became narrow when using finite ground.…”