Results 261 to 270 of about 172,799 (305)

Harmonic emission from high frequency gyrotrons

1983 Eighth International Conference on Infrared and Millimeter Waves, 1983
Second harmonic emission of power levels of ≳ 25 kW and frequencies up to 302 GHz have been achieved in a short pulse gyrotron designed for operation at the fundamental in the 110–170 GHz band. Frequency, starting current and power level measurements for several harmonic modes have been made.
J. L. Byerly, B. G. Danly, K. E. Kreischer, P. Woskoboinikow, W. J. Mulligan, R. J. Temkin   +5 more
openaire   +1 more source

High-Frequency Contrast Harmonic Imaging of Ophthalmic Tumor Perfusion

American Journal of Roentgenology, 2005
Schlottmann K, Fuchs-Koelwel B, Demmler-Hackenberg M, Gabel V-P, Scholmerich J he evaluation of symptomatic or incidentally diagnosed ophthalmic tumors usually is performed using funduscopy and Aand B-mode sonography. Additional techniques are Doppler modes [1], fluorescence or indocyanine green angiography [2], CT [3], and MR tomography [4].
Klaus, Schlottmann, Barbara, Fuchs-Koelwel, Martina, Demmler-Hackenberg, Veit-Peter, Gabel, Jürgen, Schölmerich   +4 more
openaire   +2 more sources

High-frequency, step tunable, cyclotron harmonic gyrotron

Physics of Fluids B: Plasma Physics, 1991
The performance of a high-frequency gyrotron that operates at the fundamental of the electron cyclotron frequency and its higher harmonics is described. The high frequency of 220 GHz (corresponding wavelength 1.35 mm) has been achieved at both the fundamental and second harmonic.
Toshitaka Idehara, Toshiaki Tatsukawa, Hidehiko Tanabe, Satoru Matsumoto, Kohji Kunieda, Kazuhisa Hemmi, Tomohiro Kanemaki   +6 more
openaire   +1 more source

High frequency SAW devices based on third harmonic generation

Ultrasonics, 2006
We demonstrate the third harmonic generation in a ZnO/Si layered structure to obtain high frequency SAW devices. This configuration eliminates the need of high lithography resolution and allows easy integration of such devices and electronics on the same wafer.
L, Le Brizoual, O, Elmazria, F, Sarry, M, El Hakiki, A, Talbi, P, Alnot   +5 more
openaire   +2 more sources

Effects of high-frequency harmonics on cardiac relaxation indices

American Journal of Physiology-Heart and Circulatory Physiology, 1981
This study was designed to determine the degree to which the systematic distortions in the pressure curve due to recording and filtering systems influence the relaxation indices. The purposes are 1) to analyze the dependency on the high frequencies of the relaxation and contractility parameters, 2) to determine the degree to which the catheter ...
G, Martín, J V, Gimeno, A, Ramirez, J, Cosín, J, Báguena   +4 more
openaire   +2 more sources

High-Frequency Harmonic Current Control of Power Converters

2019 IEEE Energy Conversion Congress and Exposition (ECCE), 2019
Resonant controllers are widely used in applications like active power filters and identification systems, where control of harmonics of high order (high frequency) is required. In such high-frequency range, to compensate the PWM/computational phase delay is necessary to avoid instability.
Sante Pugliese, Steffen Flacke, Zhixiang Zou, Marco Liserre   +3 more
openaire   +1 more source

High frequency resolution harmonic analysis

2016 International Conference on Development and Application Systems (DAS), 2016
The acquisition time of a real life signal limits the resolution of its spectrum, because it directly affects the orthogonality of its spectrum components. There is no spectral analysis yet to distinguish frequencies that are not orthogonal. A spectral analysis for distinguishing non orthogonal frequencies is proposed here. A system of linear equations
openaire   +1 more source

Development of high frequency, cyclotron harmonic gyrotron oscillator

Physics Letters A, 1988
Abstract The oscillation results of a high frequency gyrotron which operates at the fundamental cyctron frequency and its higher harmonics ( s =1, 2, 3) are described. The fairly high frequency of 220 GHz (corresponding wave length 1.35 mm) has been achieved at the fundamental and second harmonic of the cyclotron frequency.
Toshitaka Idehara, Toshiaki Tatsukawa, Satoru Matsumoto, Kohji Kunieda, Kazuhisa Hemmi, Tomohiro Kanemaki   +5 more
openaire   +1 more source

Reduction of stent artifacts using high-frequency harmonic ultrasound imaging

Ultrasound in Medicine & Biology, 2005
Tissue harmonic imaging (THI) has been shown to improve medical ultrasound (US) image quality in the frequency range from 2 to 10 MHz and might, therefore, also be advantageous in high-frequency US applications, like US biomicroscopy and intravascular US (IVUS).
Frijlink, ME (Martijn), Goertz, DE (David), van der Steen, Ton   +2 more
openaire   +2 more sources

Status of a high-frequency harmonic amplifier's development

IEEE Conference Record - Abstracts. 2002 IEEE International Conference on Plasma Science (Cat. No.02CH37340), 2003
Summary form only given, as follows. The harmonic amplifier (HARA) is a very compact, high efficiency amplifier that has been under development at Microwave Technologies in the past few years. The HARA uses a two-cavity system in conjunction with a spiraling beam to produce high-frequency radiation.
J.E. Velazco, P.H. Ceperley
openaire   +1 more source