Effect Of Operating Frequency Research Articles

The Effects of Operating Frequency on Wireless Power Transfer System Design and Human Health in Electric Vehicles

The Effects of Operating Frequency on Wireless Power Transfer System Design and Human Health in Electric Vehicles

Experimental investigation of thrust augmentation by ejectors on a pulse detonation engine

Utilizing gasoline as the fuel, air as oxidizer, a series of multi-cycle detonation experiments was conducted to study thrust augmentation by PDE-driven ejectors. The straight cylindrical ejectors with different inner diameter, length and inlet geometry were designed. The effects of the axial location of the ejectors relative to the end of the detonation tube, ejector length-to-diameter ratio on thrust augmentation were investigated, with the operating frequency of 25 Hz. A peak thrust augmentation level of 80.5% was achieved by adding an ejector to the exit of the detonation tube. Performance measurements of the PDE-ejector system showed that thrust augmentation is a strong function of the ejector axial position. The result indicated that there exists a maximum thrust augmentation with ejector upstream of the detonation tube exit at least. The exact location at which the maximum thrust augmentation was obtained varies with the ejector-to-PDE diameter ratio and the ejector inlet geometry. With the increase of the length-to-diameter ratio, thrust augmentation was noticeably enhanced and finally tended to a constant. There exists an optimum ejector length. In the present study, the optimum length-to-diameter ratio of ejector was 4.58. Furthermore, the effect of operating frequency on ejector thrust augmentation also investigated. The operating frequency was varied from 15 Hz to 35 Hz.

Effects of Operating Frequency on Panel-Aging and Discharge Characteristics in AC Plasma Display Panel

This paper investigates the changes in the optical and discharge characteristics during the panel-aging process in ac plasma display panel as a parameter of the operating frequency. The resulting changes in the optical and discharge characteristics, including the firing voltage, dynamic voltage margin, three-dimensional IR emission, and SEM image, are then compared for the three different operating frequencies (10, 25, and 50 kHz) during the panel-aging process. Our experimental results confirm that the 50 kHz operating frequency is very effective in obtaining the uniform surface morphology of the MgO thin film during the panel-aging process.

Effect of Operating Frequency on Plasma Characteristics of Inductively Coupled Electrode-less Lamp

To increase the efficiency and lumen output of inductively coupled electrode-less lamps, numerous studies have attempted to reduce their operating frequency. This is because if the operating frequency is reduced, a wider range of semiconductor devices can be used that enable higher lumen outputs to be obtained from these lamps. The switching loss can be reduced thus increasing the efficiency. We investigated the relationship between the operating frequency of a 50-W electrode-less lamp and its characteristics. Operating frequencies of 13.56 MHz and 135 kHz were used. The characteristics that we investigated are its starting characteristics, the plasma characteristics (such as the temperature and density of the electrons), and its efficiency in producing UV radiation. The results show that the efficiency in producing UV radiation at 135 kHz is 7% lower than that at 13.56 MHz, and that plasmas generated at operating frequencies of 135 kHz and 13.56 MHz had different electron-density and electron-temperature distributions because of the different power input positions.

Effects of Operating Frequency on Luminance Characteristics of Wide-Gap AC Plasma Display Panel

The three-electrode microdischarge characteristics of ac plasma display panels are analyzed with a wide-sustain-discharge gap of 180 mum. In particular, the luminance and consumed-power variations are examined as parameters of the operating frequency. It is found that the luminance per unit pulse decreases, and simultaneously, the consumed power per unit pulse increases with an increase in the operating frequency. For the wide-gap structure, the sustain voltage increases when increasing the operating frequency, thus causing the power consumption per unit pulse to be increased. However, the luminance per unit pulse decreases when increasing the sustain voltage, even though the power consumption per unit pulse increases with the sustain-voltage increase. As a result, it is observed that the self-erasing discharge between the sustain and address electrodes caused by the short pulsewidth under high frequency affects the luminance and consumed power. Due to the self-erasing discharge, the sustain voltage increases, and the discharge shrinkage phenomenon affecting the luminance characteristics occurs under high frequency that is up to 200 kHz with a wide-sustain-discharge gap of 180 mum.

Effect of Operating Frequency on Plasma Characteristics of Inductively Coupled Electrode-less Lamp

To increase the efficiency and lumen output of inductively coupled electrodeless lamps, numerous studies have attempted to reduce their operating frequency. This is because reducing the operating frequency enables a wide range of semiconductor devices to be used that in turn enable higher lumen outputs to be obtained from these lamps. The switching loss can be reduced thus increasing the efficiency. We investigated the relationship between the operating frequency of a 50-W electrodeless lamp and its characteristics. Operating frequencies of 13.56 MHz and 135 kHz were used. The characteristics that we investigated are its starting characteristics, the plasma characteristics (such as the temperature and density of the electrons), and its efficiency in producing UV radiation. The results show that the efficiency in producing UV radiation at 135 kHz is 7% lower than that at 13.56 MHz, and that plasmas generated at an operating frequencies of 135 kHz and 13.56 MHz had different electron-density and electron-temperature distributions because of the different power input positions.

Effect of Operating Frequency on Spatial Features of the Inductively Coupled Plasma

An unambiguous comparison has been made of the spatial features of a 27.12 and a 40.68 MHz inductively coupled plasma. Experiments were carried out with a switchable-frequency, solid-state radio-frequency generator from the Leco 2000 system. Several features of analytical significance have been evaluated in a spatially resolved fashion. Results from optimization of the magnesium ion-to-atom (Mg II/Mg I) line-intensity ratio have been compared. The volume of the two discharges was estimated from molecular nitrogen-ion emission, and a spatially resolved map of the Fe(I) excitation temperature was determined by means of a Boltzmann analysis at each spatial location. Calcium and magnesium ion-to-atom line-intensity ratios have been calculated throughout both plasmas. Finally, limits of detection are presented. The results indicate that the plasma operated at 40.68 MHz provides slightly better figures of merit, although fundamental parameters suggest a lower degree of analyte excitation. This difference is explained by examining the results of a simulation of plasmas operated at 27.12 and 40.68 MHz.

蛍光ランプの点灯周波数が電極からのバリウムスパッタリングに及ぼす影響

蛍光ランプの点灯周波数が電極からのバリウムスパッタリングに及ぼす影響

Effect of Operating Frequency on Driving-Point Impedance and Radiation Characteristics of Helical Array

A rigorous theoretical method has been developed for the calculation of driving-point impedances and far-field radiation patterns of helical array of staggered half-wave dipole radiators at different operating frequencies. The method is based on induced E M F theory. The radiators of the array are considered to be thin, linear and centre-driven. The broad-band performance for the theoretically helical array has been investigated both in respect of driving-point impedances and far-field radiation characteristics.

The Effect of Operating Frequency in the Radiation Induced Buildup of Trapped Holes and Interface States in MOS Devices

Both n-channel and p-channel MOS transistors, fabricated with a radiation hardened 3-4 um process, were irradiated at various operating frequencies and biases. The n-channel devices showed a larger rebound effect when alternately biased 'off' and 'on' during irradiation than for the cases of being biased either 'off' or 'on' during the irradiation. The p-channel devices showed a smaller threshold voltage shift when alternately biased 'off' and 'on' during irradiation compared to devices which were biased either 'off' or 'on' during the irradiation. The contributions of trapped holes and interface states on the observed threshold voltage shifts were determined through subthreshold current measurements. This research showed the source of this alternating bias effect on the radiation response of MOS devices to be reduced hole trapping and increased interface state buildup in n-channel MOS devices. In p-channel devices, reduced hole trapping is the primary source of this effect.