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Abstract. The miniaturization of devices and the increase of operating frequencies are two important issues for communication system development. This requires a high degree of integration, higher performance and lower cost. Isolator is an important non-reciprocal passive component for source protection. In most cases, the non-reciprocal effect is based on field displacement phenomenon induced by a magnetized ferrite material. In this paper we propose a new design of a coplanar isolator based on field displacement, composed of a non symmetrical coplanar transmission line, made from a ferrite layer and ground plane below.Simulations were performed using HFSS software. Measurements were made on a first 1000 µm-thick YIG film sample giving 1 dB of insertion losses and 17 dB isolation and on a second sample made from a 150 µm-thick YIG ferrite sample giving an insertion loss lower than 2 dB. Interesting applications of this isolator structure are considered.

The present paper aims at sensing the temperature. A sensor metamaterial consisting of two concentric metallic rings and a thin metallic wire deposited on the surface of BaTiO3 substrate is reported. The use of BaTiO3 makes the resonant frequency of the structure shift as the temperature varies and makes the sensor applicable in many fields of applications. Numerical simulations and theoretical results are presented and compared to each other; there was a good agreement between them. This sensor is smaller, easier to fabricate, and very sensitive to the changes in temperatures.

<span>Ultrasonic transducers are a key element that governs the performances of both generating and receiving ultrasound in an ultrasonic measurement system. Electrical impedance is a parameter sensitive to the environment of the transducer; it contains information about the transducer but also on the medium in which it is immersed. Several practical applications exploit this property. For this study, the model is implemented with the VHDL-AMS behavioral language. The simulations approaches presented in this work are based on the electrical Redwood model and its parameters are deduced from the transducer electroacoustic characteristics.</span>

A multi spiral split ring resonator based sensor is proposed for the characterization of the dielectric properties of a water ethanol mixture. The use of a narrowed microstrip line to excite the multi spiral resonator allows enhancement of excitation current and increase the sensitivity of the sensing area. Good agreement will be presented between theoretical and measured electrical parameters of the resonator in a wide frequency range from 2 to 5 GHz. The proposed sensor shows high sensitivity, miniature size, and affordable cost and above all laboratory-on-chip compatibility important for a large-scale production.

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