Vivaldi Antenna for RF Energy Harvesting

Energy harvesting is a future technology for capturing ambient energy from the environment to be recycled to feed low-power devices. A planar antipodal Vivaldi antenna is presented for gathering energy from GSM, WLAN, UMTS and related applications. The designed antenna has the potential to be used in energy harvesting systems. Moreover, the antenna is suitable for UWB applications, because it operates according to FCC regulations (3.1 – 10.6 GHz). The designed antenna is printed on ARLON 600 substrate and operates in frequency band from 0.810 GHz up to more than 12 GHz. Experimental results show good conformity with simulated performance

Higher Efficiency of Motion Estimation Methods

This paper presents a new motion estimation algorithm to improve theperformance of the existing searching algorithms at a relative lowcomputational cost. We try to amend the incorrect and/or inaccurateestimate of motion with higher precision by using adaptive weightedmedian filtering and its modifications. The median filter iswell-known. A more general filter, called the Adaptively WeightedMedian Filter (AWM), of which the median filter is a special case, isdescribed. The submitted modifications conditionally use the AWM andfull search algorithm (FSA). Simulation results show that the proposedtechnique can efficiently improve the motion estimation performance

Effects of Heavy-Ions on Soft-Magnetic Metallic Glasses Studied by Diffraction of Synchrotron Radiation

In this work, influence of $^{238}$U swift (5.9 MeV/u) heavy ions on the as-prepared Fe–Cu–Nb–Si–B metallic glass was investigated by in situ temperature X-ray diffraction of synchrotron radiation. It was observed that ion strongly affected the temperature evolution of the parameters of the first diffuse peak. It is hypothesizedthat ion irradiation induced structural rearrangement that increased the degree of disorder of the amorphous structure. During heat treatment, structural relaxation and annealing out of this ion-induced degradation took place. Consequently, the original structure was recovered as demonstrated by the behaviour of the first diffuse peak broadening and devitrification process

Susceptibility Spectroscopy in FeNiSiB Microwires

Here, we present the study on the influence of the Ni content on the magnetization processes of the amorphous glass-coated $Fe_{77.5-x}Ni_xSi_{7.5}B_{15}$ (x = 0-40) microwires. Measurement of the amplitude dependence of the complex susceptibility was used to observe the magnetization process. It is shown that the magnetization process in the presented samples runs mainly through the domain wall motion

Reversible structural transition in monocrystalline Ni2FeGaNi_{2}FeGa microwires for shape-memory applications

We report on the production and characterization of Heusler-based Ni$_2$FeGa microwires exhibiting two – wayshape memory effect. The microwires are characterized by a monocrystalline structure with a strong preferredcrystallographic orientation that shows [1 1 1] axis parallel to the wire’s axis for high-temperature L2$_1$ austenitephase, while the [0 1 7] axis is preferred for low-temperature monoclinic phase. Variation of crystallographicaxis (and corresponding easy magnetization axis) leads to 1600% variation of magnetic permeability due to a 2%strain in axial direction. Such straining is reversible immediately after production without the necessity of furtherthermal treatment. These properties give the microwire function of very sensitive SMART actuators that can beeasily produced in a large amount

Magnetic Characterization of Melt-Spun Co-Ni-Ga Ferromagnetic Superelastic Alloy

Ribbons of composition Co₄₉Ni₂Ga₃₀ have been prepared by melt-spinning method. X-ray diffraction investigation revealed single phase with B2 structure at room temperature. However, analysis of magnetization dependence of temperature suggests phase transition in the range 150-250 K. Resistivity measurements revealed similar transition with shift to higher temperatures in the presence of magnetic field

Susceptibility Spectroscopy in FeNiSiB Microwires

Here, we present the study on the influence of the Ni content on the magnetization processes of the amorphous glass-coated Fe77.5−xNixSi7.5B15 (x = 0-40) microwires. Measurement of the amplitude dependence of the complex susceptibility was used to observe the magnetization process. It is shown that the magnetization process in the presented samples runs mainly through the domain wall motion