Wideband Glass and Liquid Cylindrical Dielectric Resonator Antenna for Pattern Reconfigurable Design

A mode reconfigurable dielectric resonator antenna (DRA) to realize radiation pattern reconfiguration is presented for the first time. The DRA is composed of two zones: the inner zone is a solid cylinder fabricated by K9 glass (ϵ_r = 6.85) and the outer zone is filled with a dielectric liquid-ethyl acetate (ϵ_r = 7.1). Both of them are put into a cylindrical container fabricated by 3-D printing technology and excited by a single coaxial probe. The inner glass DRA is excited in its broadside HEM_11δ mode when the ethyl acetate is pumped out, while the conical TM_01δ mode is excited in the reconstituted cylindrical DRA when the ethyl acetate is pumped in. Consequently, a mechanical reconfiguration of broadside and conical radiation patterns can be achieved over a wide impedance bandwidth of 35.5% from 3.75 to 5.37 GHz. For demonstration, the reconfigurable DRA was fabricated and measured. The measured results of the standing wave ratio, radiation pattern, gain, and efficiency are discussed. Reasonable agreement between the measured and simulated results is observed.