Design of the Wideband and Low-Height Omnidirectional Cylindrical Dielectric Resonator Antenna Using Arced-Apertures Feeding

Abstract

This paper mainly discusses the design of wideband and low-height omnidirectional cylindrical dielectric resonator antenna (DRA). It was theoretically found that the TM-mode category of the cylindrical DRA is suitable for the wideband and low-height design using mode-merging method (TM 01δ and TM 02δ mode). An improved apertures-fed technique is proposed to excite the TM-mode DRA. The feeding consists of four arc-shaped apertures, and each aperture was fed by the in-phase signal. Based on the E-field distribution, the higher-order TM 02δ mode of the cylindrical DRA can be excited by adjusting the position of the apertures, and it fuses together with the fundamental TM 01δ mode to achieve a wideband antenna. Besides, the aperture mode further widen its impedance bandwidth. To demonstrate the idea, a wideband and low-height omnidirectional cylindrical glass DRA was designed for WLAN 5.2-GHz and 5.8-GHz applications. The experimental results show that the proposed low-height DRA (h = 0.108λ 0 ) can achieve an impedance bandwidth of 25.2 % (without aperture mode) and 34 % (with aperture mode), respectively. The bandwidth enhancement of the proposed design is significant, compared to other reported low-height TM-mode DRAs.

Compact Dielectric Resonator Antenna With Improved Bandwidth via Loading of Metal Ring

“…A conical-shaped DRA in [17] is developed to reduce the antenna height to 0.17λ0. In [15] [16], the DRA mode and the shorting-pin mode [15] or aperture mode [16] are skillfully combined to enhance the bandwidth with a height of ~0.1λ0. In [24], a lower-profile DRA (0.07λ0) with extended bandwidth by properly modifying the dielectric characteristics of the designated region is presented.…”

“…However, these reported designs tend to increase the complexity or profile of DRAs, even with the enhanced bandwidth. Low-profile DRAs with a height of approximately 0.1λ0 (where λ0 is the free-space wavelength) was exploited in [14]- [16]. Nonetheless, the achieved bandwidth in these cases was relatively narrow.…”

A Multiband Millimeter-Wave Rectangular Dielectric Resonator Antenna with Omnidirectional Radiation Using a Planar Feed

“…Moreover, four linear stubs were utilized to excite the and resonance modes of an omnidirectional cylindrical DRA to achieve circular polarization at 5.8 GHz [ 20 ]. In a more recent study, arched-aperture feeding was employed in the design of a wideband omnidirectional cylindrical DRA by merging the bandwidth of the excited TM 01δ and TM 02δ resonance modes at ~5.8 GHz [ 21 ].…”