The background harmonic fluctuation has a significant impact on the results of contribution quantification. However, existing methods, especially those applied for multiple sources scenario, usually assume that harmonics remain constant, which is inconsistent with actual operation power grid. Thus, method based minimum impedance proposed to quantify in scenario. First, roughly estimated and use...

Abstrac t -This paper presents a method to estimate the impedance response of a vibrating wire viscosity sensor. The method is based on the application of a multi-harmonic signal at the terminals of the sensor. The signal is composed by the harmonics that correspond to the frequencies at which one wants to obtain the impedance of the sensor. The impedance is determined using least-squares (LS) ...

A variational method is given for determining the essential supremum of the surface impedance of a partially coated perfect conductor from a knowledge of the far field pattern of the time-harmonic electric field at fixed frequency. It is assumed that the shape of the scatterer has been determined (e.g., by solving the far field equation and using the linear sampling method). Numerical examples ...

In this paper, a high-efficiency and compact AlGaN/GaN heterojunction field-effect transistor (HFET) power amplifier integrated with a microstrip antenna at 7.25 GHz is presented for RF front-end circuit applications. A microstrip circular sector antenna is employed as both a radiator and frequency-dependent output load. Higher order harmonics from the HFET in nonlinear operation are reactively...

In this paper the active device for a class E amplifier is modelled as switch in series with a turn on resistance ‘Ron’. Assuming an ideal harmonic load is used the switch equations for the voltage and current waveforms are reviewed and then used to examine how ‘Ron’ affects the efficiency of dc to ac power conversion. This ideal harmonic network is assumed to have optimum input impedance at th...

We consider the Helmholtz equation in the half space and suggest two methods for determining the boundary impedance from knowledge of the far field pattern of the time-harmonic incident wave. We introduce a potential for which the far field patterns in specially selected directions represent its Fourier coefficients. The boundary impedance is then calculated from the potential by an explicit fo...

A third order harmonic oscillator has been proposed based on the resonant tunneling diode pair oscillators. This oscillator has significant advantages, good stability of the oscillation frequency against the load impedance change together with capability to output higher frequencies. Proper circuit operation has been demonstrated using circuit simulations. It has been also shown that the output...

This paper presents a new method to detect high impedance faults in radial distribution systems. Magnitudes of third and fifth harmonic components of voltages and currents are used as a feature vector for fault discrimination. The proposed methodology uses a learning vector quantization (LVQ) neural network as a classifier for identifying high impedance arc-type faults. The network learns from ...