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. HEM11δ 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-i-n diodes between them. By controlling the four pairs of p-i-n 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 0.55\λ × 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.

Keywords

• Cylindrical dielectric resonator antenna
• ᵟ mode%22%2C%22default_operator%22%3A%22AND%22%7D%7D%7D"> HEM₁₁<italic xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">ᵟ</italic> mode
• polarization reconfiguration
• Wilkinson power divider
• p-i-n diodes