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Piezoelectric material is used as an active material to convert vibration energy into electrical output and so called piezoelectric energy harvesting. The harvester's dynamic model depends on several parameters such as physical dimensions, geometrical structure, mechanical and electrical properties of the piezoelectric material. The development of theoretical model for analysis and simulation is a complex task whereas complete information about these parameters is not available from the manufacturer's datasheet. In this paper, the dynamic model parameters are identified experimentally to reduce the modeling effort and to develop easily the equivalent circuit for the energy harvester (Volture, V21BL). The validation is achieved by comparing the estimated power outputs using simulation model with the real time measured values. The obtained results affirmed the potential of the adopted approach for modeling and simulation.

In this paper, a novel concept on the design of a broadband printed Yagi antenna for S-band wireless communication applications is presented. The proposed antenna exhibits a wide bandwidth (more than 48% fractional bandwidth) operating in the frequency range 2.6 GHz–4.3 GHz. This is achieved by employing an elliptically shaped coupled-directive element, which is wider compared with other elements. Compared with the conventional printed Yagi design, the tightly coupled directive element is placed very close (0.019λ to 0.0299λ) to the microstrip-fed dipole arms. The gain performance is enhanced by placing four additional elliptically shaped directive elements towards the electromagnetic field’s direction of propagation. The overall size of the proposed antenna is 60 mm × 140 mm × 1.6 mm. The proposed antenna is fabricated and its characteristics, such as reflection coefficient, radiation pattern, and gain, are compared with simulation results. Excellent agreement between measured and simulation results is observed.

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