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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
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Proceedings ArticleDOI
10 Mar 1991
TL;DR: In this article, the performance of the parallel resonant converter and the combination series/parallel resonant converters when operated above resonance in a high power factor mode is determined and compared for single-phase applications.
Abstract: The performance of the parallel resonant converter and the combination series/parallel resonant converter (LCC converter) when operated above resonance in a high power factor mode are determined and compared for single-phase applications. When the DC voltage applied to the input of these converters is obtained from a single-phase rectifier with a small DC link capacitor, a relatively high power factor inherently results, even with no active control of the input line current. This behaviour is due to the pulsating nature of the DC link and the inherent capability of the converters to boost voltage during the valleys of the input AC wave. With no active control of the input line current, the power factor depends on the ratio of operating frequency to tank resonant frequency. With active control of the input line current, near unity power factor and low input harmonic currents can be obtained. >

107 citations

Journal ArticleDOI
TL;DR: In this paper, a non-conservative model for the cantilever-sample interaction is developed and the energy dissipation in the sample is studied and the resulting power balance equations combined with the harmonic balance equations are used to estimate the model parameters.
Abstract: The atomic force microscope (AFM) is a powerful tool for investigating surfaces at atomic scales. Harmonic balance and power balance techniques are introduced to analyze the tapping-mode dynamics of the atomic force microscope. The harmonic balance perspective explains observations hitherto unexplained in the AFM literature. A nonconservative model for the cantilever–sample interaction is developed. The energy dissipation in the sample is studied and the resulting power balance equations combined with the harmonic balance equations are used to estimate the model parameters. Experimental results confirm that the harmonic and power balance tools can be used effectively to predict the behavior of the tapping cantilever.

107 citations

Journal ArticleDOI
TL;DR: Using this novel frequency tuning method, two high-power terahertz VCOs are fabricated in a 65 nm LP bulk CMOS process and the output power of these signal sources is 4 orders of magnitude higher than previous CMOS V COs and is even higher thanVCOs implemented in compound semiconductors with much higher cut-off frequencies.
Abstract: We introduce a novel frequency tuning method for high-power terahertz sources in CMOS. In this technique, multiple core oscillators are coupled to generate, combine, and deliver their harmonic power to the output node without using varactors. By exploiting the theory of nonlinear dynamics, we control the coupling between the cores to set their phase shift and frequency. Using this method, two high-power terahertz VCOs are fabricated in a 65 nm LP bulk CMOS process. The first one has a measured output power of 0.76 mW at 290 GHz with 4.5% tuning range and the output power of the second VCO is 0.46 mW at 320 GHz with 2.6% tuning range. The output power of these signal sources is 4 orders of magnitude higher than previous CMOS VCOs and is even higher than VCOs implemented in compound semiconductors with much higher cut-off frequencies.

107 citations

Proceedings ArticleDOI
01 Jan 2002

107 citations

Journal ArticleDOI
01 Jul 1933
TL;DR: In this article, the symbolic calculus has been used throughout in a complete and exact manner, by employing it for the fundamental frequency as well as for all harmonic frequencies which appear in the system.
Abstract: The investigations of the frequency variations in oscillating systems with negative nonlinear resistance were based until now on the fundamental differential equation of the simple oscillatory circuit. This method, although very exact, is not always sufficiently simple and even not always possible, especially if it concerns more complicated schemes. The symbolic calculus, although very simple in use, if applied to the nonlinear systems, gives only approximate results. The following paper represents the operation of nonlinear systems from a different point of view. Here the symbolic calculus has been used throughout in a complete and exact manner, by employing it for the fundamental frequency as well as for all harmonic frequencies which appear in the system. This could be done owing to the investigation of the negative resistance operation from the energy point of view. It was taken into consideration, that in the negative resistance characteristics i = f(v), i must be the univocal function of v, and therefore the area described by the instantaneous point of work during one cycle of the fundamental oscillation must be zero or, ⨖ idv = 0. On the other hand i and v can be considered, with regard to the external circuit connected to the negative resistance, as the sum of harmonic currents and voltages. In this way we obtain the formulas which allow the interdependence of the frequency variation and the content of harmonics to be determined.

107 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20231,223
20222,724
20211,878
20202,330
20192,612
20182,495