A Compact Dual Circularly Polarized Antenna With Wideband Operation and High Isolation

Abstract

This paper presents a dual-sense circularly polarized (CP) antenna with compact size, high isolation, and wideband characteristics. The antenna consists of a microstrip patch, an array of parasitic metal plates positioned around the patch, and a 90° branch line coupler as feeding structure. Unlike the conventional design method, we demonstrate that the wide isolation bandwidth can be achieved with an imperfect coupler and imperfect matching at the radiating element. The final design with overall dimensions of 0.59λ c × 0.59λ c × 0.06λ c (λ c is the free-space wavelength at center operating frequency) was fabricated and tested. Measurements on the fabricated prototype show that the antenna has a bandwidth of 16.5% (5.0-5.9 GHz) with port isolation of better than 15 dB. In addition, a peak broadside gain of about 6.6 dBic is attained. In comparison with other related works in literature, this antenna has advantages of wide operating bandwidth with high isolation while possessing a compact footprint. INDEX TERMSCircular polarization, dual polarization, patch antenna, wideband, high isolation Huy Hung Tran received the B. S. degree in electronics and telecommunications from

Dual Circularly Polarized Patch Antenna with Improved Interport Isolation for S-Band Satellite Communication

“…Our proposed DCP antenna offers more impedance bandwidth and peak isolation compared to those achieved by antenna in [13]. Similarly, the peak interport isolation performance of our antenna is much better than designs reported in [14][15][16][17][18][19][20][21]. e proposed dual CP antenna with high interport isolation can be used in single (monostatic) antenna-based transceiver architecture to realize single-channel full-duplex or in-band full-duplex (IBFD) communication.…”

“…e employed isolation technique is based on signal inversion mechanism to suppress the leakage from T x port to R x port. e presented dual CP antenna with high interport isolation Average isolation � 5.0 dB 770 MHz [12] ∼60 dB 399 MHz [13] ≥15.2 dB 50 MHz [14] 35 dB 200 MHz [15] 45 dB 1500 MHz [16] 50 dB 85 MHz [17] 36 dB 1340 MHz [18] 20 dB 300 MHz [19] 20 dB 150 MHz [20] 45 dB 80 MHz [21] 25 dB 900 MHz is work 72 dB 90 MHz…”

Wideband Dual-Circularly Polarized Antennas Using Aperture-Coupled Stacked Patches and Single-Section Hybrid Coupler

“…Isolation Gain (dBic) [17] 0.81×0.81 ×0.17 Table 2 shows a comparison between the performance of the proposed antenna and those of the existing wideband dual-CP designs. It is observed that the proposed antenna has a simpler configuration and a considerably wider operational bandwidth as compared to most of the dual-CP antennas with low-profile, e.g., [17], [18], [24], [25]. Differing from the prior designs [26]- [28] that require both a wideband radiator and a wideband feeding structure, the proposed antenna has achieved a wideband dual-CP radiation by a simple combination of a wideband radiator and a conventional hybrid coupler.…”

“…An air-substrate patch antenna [17] is fed by a four cross slots via a microstrip-line with multiple matching segments to achieve a dual-CP bandwidth of 16%. In [18], a square patch antenna is surrounded by 12 parasitic metal plates to obtain an operational bandwidth of 16.5%. Another way to improve the operational bandwidth of a dual-CP patch antenna is to combine a broadband radiator and a broadband feeding network to generate orthogonal fields.…”

A novel enhanced isolation microstrip dual-polarization patch antenna

“…But the structure of multilayer substrate is not only unfavorable to fabricate, but also increasing the volume and cost of antenna. In [26], [27], isolation is improved by adding parasitic patches around the same plane as the antenna, but the added parasitic patches in addition to the cost increase, the specific antenna shape needs a specific parasitic patch shape, which is not conducive to the design of the array antenna. A vertical metal wall is used to converge the surface current in the position of the vertical metal wall to achieve high isolation, but the addition of the metal wall makes the profile increase and is not conducive to the fabrication [28].…”