Polarization-Reconfigurable Cylindrical Dielectric Resonator Antenna Excited by Dual Probe With Tunable Feed Network

Abstract

A polarization-reconfigurable cylindrical dielectric resonator antenna (DRA) based on a tunable feed network is presented in this paper. HEM 11δ modes excited by two-port side-fed probes are adapted to design the proposed DRA. Polarization reconfigurable characteristic can be obtained by a tunable feed network that consists of Wilkinson equal power divider, parasitic elements used for phase shifters, and p-in diodes between them. By controlling the four pairs of p-in diode switches to active corresponding elements as effective phase shifters, two sources with equal amplitude and 0 • or ±90 • phase differences are obtained to generate linear-polarized (LP) or circular-polarized (CP) states, respectively. A fully functional prototype of the proposed antenna with the dimension of 0.55λ×0.55λ×0.14λ has been designed, fabricated, and tested. The results indicate that the proposed DRA can achieve the bandwidths of more than 30% for both impedance bandwidth and 3-dB axial ratio bandwidth at CP states, and two LP states with the impedances of 6.3% and 9.5%. Stable directional patterns and realized gains are obtained for all the states. These performances make the proposed DRA suitable for polarization diversity scenarios in communication systems. INDEX TERMS Cylindrical dielectric resonator antenna, HEM 11δ mode, polarization reconfiguration, Wilkinson power divider, p-in diodes.

Polarization Reconfigurable Slot-Fed Cylindrical Dielectric Resonator Antenna

“…In this paper, we present a new feeding configuration for a cylindrical DRA which alleviates the bandwidth limitation of the antenna presented in [10], with the ability of switching between two linear and one circular polarizations, which makes the designed DRA superior to those presented in [12] and [13]. The overlapped bandwidth of 12% obtained for the three polarizations is comparable with those reported in [11] and [13]. In this configuration, switching PIN diodes are embedded in transformers, and transformers are connected to the feeding system, adopting the technique presented in [15].…”

“…The Bandwidths for 7-dB return loss are reported about 4% and 3% for circular and linear polarizations antennas, respectively. Although, other types of switchable DRA antennas were reported later such as [11][12][13][14], to our best knowledge, none of them has addressed the bandwidth limitation of the DRA reported in [10].…”

“…The dual-probe fed cylindrical DRA in [11] generates two linear polarizations (LPs) and two circular polarizations (CPs) using eight PIN diodes. Although a very large bandwidth of 30% is reported for LPs, the matching bandwidth of two CPs are 6.3% and 9.5%.…”

“…In this configuration, switching PIN diodes are embedded in transformers, and transformers are connected to the feeding system, adopting the technique presented in [15]. Since only two PIN diodes are included in the feeding circuit, the antenna system is simpler compared to those reported in [11,13,14]. In addition, the switching procedure for the antenna is faster than that for the antenna presented in [12].…”

Antenna for Ultra-Wideband Applications With Non-Uniform Defected Ground Plane and Offset Aperture-Coupled Cylindrical Dielectric Resonators

“…Much research has focused on cylindrical DRAs [28], [37]- [40]. In [38] and [39], the DRA device is used as sensors for wireless networks and liquid chemical detection applications, respectively.…”