Triple-Band Dual-Sense Circularly Polarized Hybrid Dielectric Resonator Antenna

• Main Authors: Amir Altaf, Munkyo Seo
• Format: Article
• Language: English
• Published: MDPI AG 2018-11-01
• Series: Sensors
• Subjects: dielectric resonator antenna (DRA); hybrid antenna; multi-band; square microstrip ring; triple-band circular polarization
• Online Access: https://www.mdpi.com/1424-8220/18/11/3899

In this paper, a triple-band dual-sense circularly polarized (CP) hybrid dielectric resonator antenna is proposed. A modified hexagonal dielectric resonator (DR) is top-loaded with a square microstrip ring (SMR). A vertical-tapered-strip connected to a 50-<inline-formula> <math display="inline"> <semantics> <mo>&#937;</mo> </semantics> </math> </inline-formula> microstrip line is used to excite the proposed antenna. It is found that the lower and central CP bands correspond to left-handed circular polarization and are produced by the TM<inline-formula> <math display="inline"> <semantics> <msub> <mrow></mrow> <mn>11</mn> </msub> </semantics> </math> </inline-formula> and TE<inline-formula> <math display="inline"> <semantics> <msub> <mrow></mrow> <mn>111</mn> </msub> </semantics> </math> </inline-formula> modes of the SMR and modified hexagonal DR, respectively. The upper CP band is formed by the combination of the quasi-TM<inline-formula> <math display="inline"> <semantics> <msub> <mrow></mrow> <mn>21</mn> </msub> </semantics> </math> </inline-formula> mode of the SMR and quasi-TE<inline-formula> <math display="inline"> <semantics> <msub> <mrow></mrow> <mn>111</mn> </msub> </semantics> </math> </inline-formula> mode of the DR that exhibits right-handed circular polarization. The measurement results of the fabricated prototype show triple-band response for |S<inline-formula> <math display="inline"> <semantics> <mrow> <msub> <mrow></mrow> <mn>11</mn> </msub> <mrow> <mo>|</mo> <mo>&lt;</mo> </mrow> </mrow> </semantics> </math> </inline-formula> &#8722;10 dB with impedance bandwidths (IBWs) of 17.4% (1.75&#8315;2.03 GHz), 28.13% (2.23&#8315;2.96 GHz), and 2.97% (3.65&#8315;3.76 GHz) in the lower, central, and upper bands, respectively. The measured 3 dB axial ratio bandwidths lying within &#8722;10 dB IBWs are 3.69% (1.86&#8315;1.93 GHz), 5.46% (2.67&#8315;2.82 GHz), and 2.15% (3.68&#8315;3.76 GHz) along with the peak gains of 5 dBic, 5.28 dBic, and 2.36 dBic in the lower, central, and upper bands, respectively.