A Pure-Water Inverted-L Antenna With Frequency Reconfigurability

Abstract

This paper proposes a novel pure-water antenna with an inverted-L structure and frequency reconfigurability. It consists of a transparent double-layer resin container with water, a ground plane and a probe feed inserting into the container. The inverted-L structure of transparent container is exquisitely designed to shape the liquid. By controlling the filling status of water, i.e., only occupying inner layer (state 1) or the whole container (state 2), the radius of water rod is altered, which results in frequency reconfigurability. The radiation principle is based on the high-order mode of dielectric waveguide. Reflection coefficients of these two different states have been here provided. It is found that the working frequency can be tuned from 1.1 to 1.86 GHz. It should be mentioned that more layers and thinner layer thickness can be used to achieve continuous and wide tuning range from 1.1 to 2.2 GHz. The proposed antenna shows advantages of low cost, low profile, wide frequency tuning range and broadside radiation.