An Electronically-Switched Frequency-Agile Hybrid Dielectric Resonator Antenna With a Fixed Reconfigurable Circularly Polarized Band

In this article, an electronically-controlled frequency-agile hybrid dielectric resonator antenna is presented that also produces a reconfigurable circularly polarized (CP) wave over a specific frequency range. Two L-shaped metallic strips are placed adjacent to a partial ground plane that can be shorted/detached in four combinations using two PIN diodes (D1 and D2). Frequency reconfigurability is achieved by switching from both OFF to at least one ON state to yield a single and dual-band responses for the former and latter, respectively. The Eigen mode simulation reveals that the upper-band is mainly attributed to the quasi-TE delta 21 mode of the rectangular dielectric resonator. The lower-band in one and two ON-states arises due to the dielectric-loaded monopole antenna and the strip-loaded partial ground plane, respectively. The ON-OFF state produces a right-handed CP wave at the lower band that can be reconfigured to a left-handed CP wave by switching to OFF-ON state. A fabricated sample is measured and simulation results are validated. The measured -10 dB impedance bandwidths for OFF-OFF, ON-ON, OFF-ON, and ON-OFF are 13.31% (4.42-5.05 GHz), 11.30% (2.17-2.43 GHz)/27.43% (3.68-4.85 GHz), 30.64% (2.46-3.35 GHz)/17.94% (4.16-4.98 GHz), and 26.57% (2.48-3.24 GHz)/18.7% (4.12-4.97 GHz), respectively. The measured 3 dB axial ratio bandwidths are 12.20% (2.54-2.87 GHz) and 10.95% (2.59-2.89 GHz) when D1 and D2 are turned-ON alternatively.