A Low-Profile and High-Aperture-Efficiency Hexagonal Circularly Polarized Microstrip Antenna Array

Abstract

In this letter, a high aperture efficiency (AP), right hand circularly polarized (RHCP), sequentially rotated hexagonal microstrip antenna array, working at GPS L1 band, is proposed. The proposed antenna design is placed on the hexagonal top of a floating sensor node for ocean and marine monitoring applications. To use the hexagonal area effectively and maximize the AP, CP microstrip antenna elements have been distributed centrosymmetric about the origin on the hexagonal substrate. Typically, the AP is enhanced by using thicker substrates, particularly with air gaps. Here, we show a high AP on a very lowprofile substrate (0.011 for the lowest operating frequency) by properly choosing the distance of the antenna elements from the center of the array. The proposed design, based on H-shaped aperture-coupled circular patches, demonstrates a measured gain of 12.4 dBi and an AP of 101%, which is one of the highest reported AP for one of the lowest profile sequentially rotational array.

Hexagonal-Triangular Combinatorial Structure Based Dual-Band Circularly Polarized Patch Antenna for GAGAN Receivers

“…Though the antenna in [19] is smaller in size, it has a low gain level of less than 0.5 dBi due to a relatively smaller ground plane and is linearly polarized. In [15], [17], [20], [23], the gain performance s higher with wide IBW, but the antenna is bigger with a complex feed structure making it difficult for fabrication. Even though the size of the antennas in [14], [16], [18] is big, the gain is observed to be moderate with narrow 3 dB ARBW in [14], [16].…”

“…Though it is compact, the gain is less than 0.5 dBi due to the smaller ground plane. The gain is improved in [20], by incorporating a sequentially rotated hexagonal patch array on a larger substrate resulting in a gain greater than 5 dBi with wide IBW. Though the single antenna is omni-directional, the hexagonal array exhibits a narrow radiation pattern due to the thicker substrate.…”