Open-ended dielectric-filled waveguide antenna for underwater usage

In wireless short-range underwater communication a trend towards higher operating frequencies and bandwidth can be noticed in order to increase channel capacity and throughput. For launching electromagnetic waves typically low-directive wire antennas are employed. In this work a new kind of underwater antenna is presented for the 2.4GHz industrial, scientific and medical (ISM) band, based on a dielectric filled open-ended waveguide. The antenna is designed as impedance matching transformer allowing a connection of conventional 50 Ω coaxial cables. The measured 10 dB bandwidth in fresh water is approx. 550MHz (22 %). Compared to a conventional monopole antenna an increase in receive power of approx. 14 dB can be achieved.