Frequency tunable fluidic annular slot antenna

A coplanar waveguide fed annular slot antenna with fluidic housing is investigated. The channels of the housing are filled either with air, acetone, or de-ionized (DI) water to dynamically change the resonant frequency of the antenna. Two channels are fabricated perpendicular to the feedline on the half of the annular slot opposite the feed. The outer channel is shown to control the first resonance of the antenna with a tunable frequency range from 3 GHz to 4.2 GHz. The second channel, which is closer to the center of the antenna, is shown to control the second resonance of the antenna with a tunable range of 4.4 to 7.9 GHz.