This paper adopts a fractional calculus perspective to describe a non-linear electrical inductor. First, the electrical impedance spectroscopy technique is used for measuring the impedance of the device. Second, the experimental data is approximated by means of fractional-order models. The results demonstrate that the proposed approach represents the inductor using a limited number of parameters, while highlighting its most relevant characteristics.

This work focuses on the concept of operation and possibility of using a tuned inductor in electrical power systems with adaptive features. The idea presented here for the operation of the inductor is a new approach to the design of such devices. An example of a power adaptive system is a device for improving the quality of electricity. The negative impact of nonlinear loads on the operation of a power grid is a well-documented phenomenon. Hence, various types of “compensators” for reactive power, or for both reactive and distortion power, are used in electrical systems as a preventive measure. The concept of an inductor presented here offers wider possibilities for power compensation in power supply systems, compared to traditional solutions involving compensators based on fixed inductors. The use of the proposed solution in an adaptive compensator is only one example of its possible implementation in the area of power devices. In this work, we discuss the structure of the compensator, the basic aspects of the operation of the inductor, the results of simulation studies and the results of measurements obtained from a prototype.

The purpose of this paper is to propose a model of a novel quasi-resonant boost converter with a tapped inductor. This converter combines the advantages of zero voltage quasi-resonant techniques and different conduction modes with the possibility of obtaining a high voltage conversion ratio by using a tapped inductor, which results in high converter efficiency and soft switching in the whole output power range. The paper contains an analysis of converter operation, a determination of voltage conversion ratio and the maximum voltage across power semiconductor switches as well as a discussion of control methods in discontinuous, critical, and continuous conduction modes. In order to verify the novelty of the proposed converter, a laboratory prototype of 300 W power was built. The highest efficiency η  = 94.7% was measured with the output power P_o =  260 W and the input voltage V_in = 50 V. The lowest efficiency of 90.7% was obtained for the input voltage V_in  = 30 V and the output power P_o = 75 W. The model was tested at input voltages (30–50) V, output voltage 380 V and maximum switching frequency 100 kHz.

In conventional finite element simulations, foil windings with thin foils and with a large number of turns require many mesh elements. This renders models quickly computationally infeasible. This paper uses a homogenized foil winding model and approximates the voltage distribution in the foil winding domain by globally supported polynomials. This way, the small-scale structure in the foil winding domain does not have to be resolved by the finite element mesh. The method is validated successfully for a stand-alone foil winding example and for a pot inductor example. Moreover, a transformer equipped with a foil winding at its primary side is simulated using a field-circuit coupled model.

Studies of noise properties of thick-film conducting lines from Au or PdAg conductive pastes on LTCC or alumina substrates are reported. Experiments have been carried out at the room temperature on samples prepared in the form of meanders by traditional screen-printing or laser-shaping technique. Due to a low resistance of the devices under test (DUTs), low-frequency noise spectra have been measured for the dc-biased samples arranged in a bridge configuration, transformer-coupled to a low-noise amplifier. The detailed analysis of noise sources in the signal path and its transfer function, including the transformer, has been carried out, and a procedure for measurement setup self-calibration has been described. The 1/f noise component originating from resistance fluctuations has been found to be dominant in all DUTs. The analysis of experimental data leads to the conclusion that noise is produced in the bends of meanders rather than in their straight segments. It occurs that noise of Au-based laser-shaped lines is significantly smaller than screen-printed ones. PdAg lines have been found more resistive but simultaneously less noisy than Au-based lines.

This paper is devoted to a detailed experimentally based analysis of applicability of vector network analyzers for measuring impedance of surface mount inductors with and without DC bias. The measurements are made using custommade bias tees and a test fixture with an ordinary vector network analyzer. The main attention in the analysis is focused on measurement accuracy of an impedance of surface mount inductors. Measurement results obtained with a vector network analyzer will also be compared to those obtained by using an impedance analyzer based on auto-balancing bridge method.

In this paper, a three-air-gapped structure of a ferrite core for a resonant inductor is proposed. The electromagnetic and thermal field models are built using a 3D finite element method. Compared with the conventional signal-air-gapped structure of a ferrite core, the simulation and analysis results show that the proposed three-air-gapped ferrite core resonant inductor can reduce eddy-current loss and decrease temperature rise. In addition, the optimal position of air-gapped is presented.

This paper presents active inductor based VCO design for wireless applications based on analysis of active inductor models (Weng-Kuo Cascode active inductor & Liang Regular Cascode active inductor) with feedback resistor technique. Embedment of feedback resistor results in the increment of inductance as well as the quality factor whereas the values are 125.6@2.4GHz (Liang) and 98.7@3.4GHz (Weng-Kuo). The Weng-Kuo active inductor based VCO shows a tuning frequency of 1.765GHz ~2.430GHz (31.7%), while consuming a power of 2.60 mW and phase noise of -84.15 dBc/Hz@1MHz offset. On the other hand, Liang active inductor based VCO shows a frequency range of 1.897GHz ~2.522GHz (28.28%), while consuming a power of 1.40 mW and phase noise of -80.79 dBc/Hz@1MHz offset. Comparing Figure-of-Merit (FoM), power consumption, output power and stability in performance, designed active inductor based VCOs outperform with the stateof- the-art.

In the paper an improved method of calculation of the inductance and capacitances in the ?1 circuit for Class A, AB, B, and C resonant power amplifiers is presented. This method is based on an assumption that the quality factor of the inductor is inite and the capacitors are lossless. The input parameters for calculations are the amplifier load resistance, the transistor load resistance, the quality factor of the inductor, the loaded quality factor of the designed circuit, and the operating frequency. The presented method allows reducing the required regulation range of ?1 circuits elements In built resonant amplifiers as compared to the traditional calculation methods assuming lossless capacitors and inductor. This advantage is important, in particular, for long- and medium-wave transistor power amplifiers, where capacitances in ?1 circuits are high comparing to typical trimming capacitors.