Metasurfaced, broadband, and circularly polarized liquid antennas using a simple structure

A novel broadband circularly polarized (CP) antenna using organic ionic liquid resonators is presented in this communication for the first time. The antenna is excited by inserting a new feeding structure into the liquid which is relatively simple but significantly improves the bandwidth and CP performance of traditional single probe-fed dielectric resonator antennas (DRAs). The proposed liquid antenna is loaded with a metasurface (MS) to further improve the impedance matching and CP characteristics. A design example of the proposed antenna shows a relatively wide fractional impedance bandwidth and CP bandwidth of 51.4% and 34.2%, respectively. In addition, the proposed liquid DRA has a reduced structural complexity and a compact size compared with the conventional DRAs with a similar performance. The design methodology presented in this communication can be further exploited for a range of new liquid DRA designs and expand the design freedom and flexibility of such antennas which may have significant implications in future antenna designs using the new liquid materials.