Reconfigurable RHCP-to-LP Helical Antenna Made of Pure Water

A polarization-reconfigurable pure-water helical antenna operating at 1.6 GHz is presented in this paper, which consists of two water helixes with inversed rotational directions connected in series. By changing the water height, a switch between right-handed circular polarization (RHCP) and linear polarization (LP) is achieved. Measured results show that the proposed RHCP-to-LP antenna has an overall impedance bandwidth (|S
₁₁
| <; -10 dB) of 79.1% for the two polarizations, and an axial ratio (AR) bandwidth (AR<; 3 dB) of 51.4% for RHCP.