An efficient technique for the design of miniaturized wireless sensors within liquids

Recently, novel wireless sensor network architectures, suitable to monitor fluids characteristics from inside a conduit, have been proposed in the literature. These techniques require the implementation of a sensor equipped with an electromagnetic front-end able to transmit through a dissipative medium. This requires antennas with high transmission efficiency, even if inserted in liquids, in confined spaces, hence with high attention to the reduction of the dimensions. The present paper introduces an efficient design procedure that allows an easy and fast definition of the microwave circuit. The procedure is particularly suitable when the antenna is inserted in a complex scenario, with several media in the near field of the radiator.