Topic
Harmonic
About: Harmonic is a research topic. Over the lifetime, 44833 publications have been published within this topic receiving 495922 citations. The topic is also known as: overtone & partial.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this article, a single microstrip patch antenna having two-dimensional photonic bandgap (PBG) in the ground has been demonstrated experimentally, and the effectiveness of the PBG structure is discussed for the suppression of the resonance at the harmonic frequencies of the antenna.
Abstract: In this work, the single microstrip patch antenna having two-dimensional photonic bandgap (PBG) in the ground has been demonstrated experimentally, and the effectiveness of the PBG structure is discussed for the suppression of the resonance at the harmonic frequencies of the antenna. Experimental results indicate that the radiation patterns at the harmonic frequencies can be drastically diminished comparing with the normal microstrip patch antenna without the PBG structure. For instance, the radiation to the forward of the PBG antenna is suppressed at more than 15 dB at the third harmonic frequency.
199 citations
TL;DR: In this article, the authors developed explicit expressions for the cross-spectral density between pairs of sensors and the wave-number-frequency spectrum projected onto the line joining these sensors, when they are placed in arbitrary positions in noise fields which are described by an arbitrary directional distribution of uncorrelated plane waves.
Abstract: Explicit expressions are developed for the cross‐spectral density between pairs of sensors and the wavenumber‐frequency spectrum projected onto the line joining these sensors, when they are placed in arbitrary positions in noise fields which are described by an arbitrary directional distribution of uncorrelated plane waves. The approach is to expand the directional distribution in spatial harmonics. Each harmonic leads to a corresponding term, with the same coefficient, in series representations for the cross‐spectral density function and the wave‐number‐frequency spectrum. The approach particularly attractive when the field can be adquately represented by a relatively small number of harmonics. Both two‐ and three‐dimensional fields are considered. The approach is applied to the vertical directionality of ambient sea noise and is related to some existing models of ambient sea noise. Some new models are presented. Results are compared with reported experimental data and found to be in good agreement over a wide frequency range.
198 citations
TL;DR: In this paper, the second order harmonic of a Lamb wave propagating in a metallic plate is measured using a hybrid wedge generation and laser interferometric detection system, and the results show that the proposed procedure is able to characterize the inherent material nonlinearity of two different aluminum plates whose absolute nonlinearness parameters are known from longitudinal wave measurements.
Abstract: The objective of this research is to develop an accurate and reliable procedure to measure the second order harmonic of a Lamb wave propagating in a metallic plate. There are two associated complications in measuring these nonlinear Lamb waves, namely, their inherent dispersive and multimode natures. To overcome these, this research combines a time-frequency representation with a hybrid wedge generation and laser interferometric detection system. The effectiveness of the proposed procedure is demonstrated by characterizing the inherent material nonlinearity of two different aluminum plates whose absolute nonlinearity parameters are known from longitudinal wave measurements.
198 citations
18 Jun 2006
TL;DR: The authors' views on some of the more ambiguous elements of IEEE Std 519-1992 and on the application of harmonic limits in general are presented.
Abstract: IEEE Std 519-1992 is a useful document for understanding harmonics and applying harmonic limits in power systems. Despite many years of good use there is still some confusion about how to apply certain aspects of the standard. This paper discusses some of those, as well as related issues that are helpful in working with harmonic limits. There is considerable debate as to precisely how some elements of IEEE Std 519-1992 should be interpreted. This paper presents the authors’ views on some of the more ambiguous elements of the standard and on the application of harmonic limits in general.
197 citations
TL;DR: In this paper, an approximate analysis of LLC resonant converter with capacitive filter operating above and below resonance is presented, and an equivalent ac resistance model of the rectifier valid for discontinuous as well as continuous conduction modes is proposed.
Abstract: This paper presents an approximate analysis of LLC resonant converter with capacitive filter operating above and below resonance. An equivalent ac resistance model of the rectifier valid for discontinuous as well as continuous conduction modes is proposed. The dc voltage conversion ratio is then obtained using the fundamental harmonic approximation analysis method. Based on the analysis, LLC converter design plots and guidelines are suggested. The theory is verified by simulation and experiment.
197 citations