Ionic liquid antenna

A new antenna is described using salt dissolved in water as the radiating element. Recently, it has been reported by the radio amateur community that stimulating a column of salt water, with a salinity in excess on 70 parts per thousand (ppt), at HF frequencies (<30 MHz) produces usable antennas. A simple monopole antenna was constructed and its reflected impedance and radiation efficiency measured for salt solutions of 2 conductivities and 2 monopole diameters. Two antennas were constructed, 25 mm and 50 mm in diameter, with salt solution at 35 ppt and 70 ppt. The resonant frequency was found to be inversely proportional to salt solution column height, with bandwidths of /spl sim/1 GHz (-10 dB S11 points) at 1.3 GHz. Radiation efficiency, using the Wheeler cap method, was found to be 50-70%. This novel antenna structure has applications in wide band antennas. Since the antenna can alter its shape easily, it also has applications in reconfigurable antennas.