Compact organic liquid dielectric resonator antenna for air pressure sensing using soft material

For the first time, a flexible and deformable liquid dielectric resonator antenna (LDRA) is proposed for air pressure sensing. The proposed LDRA can be made very compact as it has employed liquidized organic dielectric with high dielectric constant (~ 33) with low loss tangent (~ 0.05). Here, a soft elastomer container has been fabricated using soft-lithography method for holding the liquid, and an air cavity is tactfully embedded into the central part of a cylindrical DRA to form an annular structure that can be used for sensing air pressure. It will be shown that the inclusion of the air cavity is essential for making the antenna structure sensitive to pressure changes. Simulations and experiments have been conducted to verify the functionalities of the proposed organic LDRA as microwave radiator and as air pressure sensor. It has been proven to have higher antenna gain than the water LDRA in the frequency range of 1.8–2.8 GHz, while achieving a good air pressure sensitivity of 270 MHz/bar.