A Cross-Shaped Dielectric Resonator Antenna for Multifunction and Polarization Diversity Applications

Abstract

Abstract-This letter proposes a multifunction cross-shaped dielectric resonator antenna (DRA) with separately fed broadside circularly polarized (CP) and omnidirectional linearly polarized (LP) radiation patterns. These distinct radiation patterns are achieved in overlapping frequency bands by exciting two different modes in a single dielectric resonator (DR) volume. This letter also investigates the effect of the feeding geometry on the mutual coupling between the modes and concludes that an asymmetric feeding degrades the orthogonality of the modes and thus increases the interport coupling coefficient. By using a symmetric feeding, the coupling coefficient can be significantly reduced to below 30 dB in the frequency band common to both operation modes. The experimental results show a good agreement with simulation and demonstrate a broadside CP operation over a bandwidth of 6.8%, which overlaps with the omnidirectional LP impedance bandwidth of 38.5%. The proposed antenna could be used not only as multifunction, but also as polarization diversity antenna due to the overlapping dual-feed CP and LP operation.

Combination of the Three Types of Diversity to Design High-Capacity Compact MIMO Terminals

“…Antennas providing combinations of the different types of diversities already exist in the literature. For instance, we can find compact designs for antennas with polarization diversity using the same radiation pattern as in [8], but also with different radiation patterns for each polarization [17]. Both cases refer to two-port antennas, but also a four-port antenna corresponding to two radiation patterns, each of them with two polarizations, can be implemented if desired as in [16], but assuming a more complicated and bigger antenna.…”

Linearly polarized asymmetric dielectric resonator antenna for 5.2-GHz WLAN applications

“…[3,4] Various efforts on DRAs have been reported to achieve wideband operation such as introducing an air gap between the DRA and ground plane, [5] multilayer stacking of dielectric materials, [6] fractal approach on DRA. [7] Using the advantage of DR structure, flexibility of various geometries of RDRAs such as L-shaped, [8] T-shaped, [9] H-shaped, [10] Z-shaped, [11] and X-shaped [12] have also been proposed for bandwidth enhancement for broadside radiation. Though the proposed antennas were wideband and compact in size but due to multiband resonances, *Corresponding author.…”

Hybrid patch/stacked hollow dielectric resonator antenna operating in dual mode radiations

“…A CP cylindrical DRA with omnidirectional and broadside radiation patterns for pattern diversity was designed [3]. A crossed shaped DRA can generate CP broadside and LP omnidirectional radiation patterns with the excitation of Quasi-TM 111 and TE 111 modes [4]. For cylindrical DRA, the TM 01 and HEM 11 modes can be used to obtain the LP and CP radiation patterns simultaneously [5].…”