Broadband “in-series multistation” rf cavity with low voltage standing wave ratio

2005 ◽  
Vol 76 (5) ◽  
pp. 053306
Author(s):  
Toshiyuki Misu ◽  
Nobuyuki Miyahara ◽  
Akinori Sugiura ◽  
Satoru Hojo ◽  
Mitsutaka Kanazawa ◽  
...  
Keyword(s):  
Standing Wave ◽  
Low Voltage ◽  
Voltage Standing Wave Ratio ◽  
Rf Cavity ◽  
In Series

THEORY AND DESIGN OF A COAXIAL SUPPORTING BEAD MADE OF COMPOSITE DIELECTRICS

1961 ◽  
Vol 39 (6) ◽  
pp. 926-934
Author(s):  
Gilbert H. Owyang
Keyword(s):  
Standing Wave ◽  
Frequency Ratio ◽  
Low Voltage ◽  
Coaxial Line ◽  
Wide Band ◽  
Voltage Standing Wave Ratio ◽  
Physical Parameters ◽  
Minimum Frequency ◽  
Typical Design

The effect due to the presence of a single supporting bead made of composite dielectrics in a coaxial line is being studied. A formula correlating the standing wave ratio caused by the bead and the physical parameters of the bead is derived. A bead of this type may be designed to have very low voltage standing wave ratio (VSWR) over a very wide band of frequency. A typical design using quartz and air as dielectrics is given, and the calculated VSWR is below 1.003 over a bandwidth whose maximum to minimum frequency ratio is as high as 13:1.

Fabrication of Horn Antenna for Microwave Application

2020 ◽  
Vol 6 (2) ◽  
pp. EC-17-EC-27
Author(s):  
Yusuf Durachman ◽  
Keyword(s):  
Standing Wave ◽  
Power Transmission ◽  
Low Voltage ◽  
Horn Antenna ◽  
High Gain ◽  
Transmission Efficiency ◽  
Voltage Standing Wave Ratio ◽  
Microwave Application ◽  
Microwave Applications ◽  
Novel Design

This paper contains a novel design of a horn antenna control system for microwave applications. Using “Fermat’s principle” the horn antenna is designed and fabricated. For microwave applications, high gain and low voltage standing wave ratio(VSWR) is needed, so for that purpose horn antenna is fabricated. In a previous paper, they designed the Yagi Uda antenna which is used for multiple driven elements by the method called maximum power transmission efficiency. For multiple driven elements, the horn antenna cannot be fabricated. If suppose yagi uda is fabricated using the principle called Fermat's, the system can't achieve more gain and low voltage standing wave ratio. Yagi uda antenna can achieve only a high voltage standing wave ratio. To reduce the problems in the existing paper, our paper designs a horn antenna to achieve high gain and low voltage standing wave ratio( VSWR) which is used for microwave applications to transmit microwaves from a waveguide out into space or collect microwaves into a waveguide for the reception.

scholarly journals A Novel Hybrid LDC Converter Topology for the Integrated On-Board Charger of Electric Vehicles

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3603
Author(s):  
Vu-Hai Nam ◽  
Duong-Van Tinh ◽  
Woojin Choi
Keyword(s):  
Low Voltage ◽  
Operating Conditions ◽  
Maximum Efficiency ◽  
Battery Charger ◽  
Forward Converter ◽  
Vehicle To Grid ◽  
Circulating Current ◽  
In Series ◽  
Converter Topology ◽  
Output Capacitor

Recently, the integrated On-Board Charger (OBC) combining an OBC converter with a Low-Voltage DC/DC Converter (LDC) has been considered to reduce the size, weight and cost of DC-DC converters in the EV system. This paper proposes a new integrated OBC converter with V2G (Vehicle-to-Grid) and auxiliary battery charge functions. In the proposed integrated OBC converter, the OBC converter is composed of a bidirectional full-bridge converter with an active clamp circuit and a hybrid LDC converter with a Phase-Shift Full-Bridge (PSFB) converter and a forward converter. ZVS for all primary switches and nearly ZCS for the lagging switches can be achieved for all the operating conditions. In the secondary side of the proposed LDC converter, an additional circuit composed of a capacitor and two diodes is employed to clamp the oscillation voltage across rectifier diodes and to eliminate the circulating current. Since the output capacitor of the forward converter is connected in series with the output capacitor of the auxiliary battery charger, the energy from the propulsion battery can be delivered to the auxiliary battery during the freewheeling interval and it helps reduce the current ripple of the output inductor, leading to a smaller volume of the output inductor. A 1 kW prototype converter is implemented to verify the performance of the proposed topology. The maximum efficiency of the proposed converter achieved by the experiments is 96%.

Design of Antipodal Vivaldi Antenna Array

2013 ◽  
Vol 380-384 ◽  
pp. 3465-3468
Author(s):  
Hai Bo Tang ◽  
Xiao Zhong Shui
Keyword(s):  
Antenna Array ◽  
Standing Wave ◽  
Voltage Standing Wave Ratio ◽  
Radiation Characteristics ◽  
Vivaldi Antenna ◽  
Cross Structure ◽  
Structure Array

Firstly in this paper,an antipodal Vivaldi antenna is designed.The bandwidth is from 6GHz to 18GHz. The simulated results show good electric performance and the voltage standing wave ratio is less than 2 in the whole bandwidth.Secondly depending on this unit,this paper designs two kinds of arrays and estimates their radiation characteristics,respectively.The one array is a 1×8 array and the another array is a X-cross structure array with four elements.

A scalable strategy toward compliant tandem yarn-shaped supercapacitors with high voltage output

2021 ◽  
Author(s):  
Juan Zhang ◽  
Qingli Xu ◽  
Xiangyu Qian ◽  
Xinhou Wang ◽  
Kun Zhang
Keyword(s):  
High Voltage ◽  
Aqueous Electrolyte ◽  
Low Voltage ◽  
Voltage Output ◽  
In Series

Yarn-shaped supercapacitors (YSSCs) based on aqueous electrolyte exhibit relatively low voltage output due to the low decomposition voltage of water (~1.23 V). Applying organic-based electrolyte or connecting YSSCs in series...

Efficient Approach to LVRT Capability of DFIG-Based Wind Turbines under Symmetrical and Asymmetrical Voltage Dips Using Dynamic Voltage Restorer

2017 ◽  
Vol 8 (2) ◽  
pp. 945 ◽  
Author(s):  
Kiarash Azizi ◽  
Murtaza Farsadi ◽  
Mohammad Farhadi Kangarlu
Keyword(s):  
Wind Turbines ◽  
Low Voltage ◽  
Normal Operation ◽  
Dynamic Voltage Restorer ◽  
Volume Weight ◽  
Voltage Restorer ◽  
Voltage Dips ◽  
Dynamic Voltage ◽  
In Series ◽  
Grid Side

<span>The capability of low-voltage ride-through (LVRT) of doubly fed induction generator (DFIG) has been considered as an essence for grid code requirements. Any unbalance on the grid side causes the rotor current of the generator to rise which leads to saturate the dc-link of the back-to-back converter or even destroy it. To meet this requirement, a dynamic voltage restorer (DVR) without dc-link energy storage elements is utilized to compensate any disturbance imposed to the DFIG wind turbine system. On the time of any disturbance or fault, DFIG and DVR are properly controlled in order to compensate the specified faulty phase uninterruptedly. DVR is connected in series to the grid and by injecting instantaneous compensating voltage, prevents the stator voltage from rapid changing; consequently, the rotor side converter can accomplish its normal operation. As voltage dips are the most common grid faults subjected to DFIGs, this paper investigates both symmetrical and asymmetrical voltage dips caused by grid faults. The independent and instantaneous phase voltage compensation, less volume, weight, and cost are the merits to utilize the proposed DVR along with DFIG wind turbines. PSCAD/EMTDC based simulations verifies the capabilities of the proposed technique for the LVRT capability of DFIG.</span>

GROUNDING EFFECT ON THE PERFORMANCE OF UWB ICE-CREAM CONE ANTENNA

2016 ◽  
Vol 78 (5-10) ◽  
Author(s):  
Siti Rohmah Mohamed Kamaruddin ◽  
Ahmad Rakimi Mohamed ◽  
Abu Bakar Ibrahim
Keyword(s):  
Dielectric Constant ◽  
Standing Wave ◽  
Ice Cream ◽  
Voltage Standing Wave Ratio ◽  
Planar Antenna ◽  
Radiation Characteristics ◽  
Dielectric Thickness ◽  
Antenna Performance ◽  
Spectrum Band ◽  
Cst Microwave Studio

In this paper, presents the grounding effect on the performance of UWB Ice Cream Cone Antenna communication. This planar antenna designed on a FR4 substrate with the dielectric thickness, 1.6 mm and the dielectric constant Ɛr, 4.7. An analysis results for antenna with different parameter for width of feed as a ground has been investigated. The antennas were designed and simulated by using CST Microwave Studio Simulation. The proposed antenna performs from 4 GHz to 11 GHz spectrum band. The return losses, S11 for the suggestion antenna must be below than -10dB and voltage standing wave ratio, VSWR less than 2. The best grounded single ice cream cone antenna performance was obtained at 5.688 GHz with antenna sizes is 12 mm x 14.5 mm. The antenna gives omnidirectional radiation characteristics from UWB spectrum band requirement with reasonable gain values.

scholarly journals Experimental Investigation of the Prestrike Characteristics of a Double-Break Vacuum Circuit Breaker under DC Voltages

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3217
Author(s):  
Yun Geng ◽  
Xiaofei Yao ◽  
Jinlong Dong ◽  
Xue Liu ◽  
Yingsan Geng ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Direct Current ◽  
Experimental Work ◽  
Low Voltage ◽  
Circuit Breaker ◽  
Circuit Breakers ◽  
Vacuum Circuit Breaker ◽  
In Series ◽  
The Difference ◽  
Single Break

The prestrike phenomenon in vacuum circuit breakers (VCBs) is interesting but complicated. Previous studies mainly focus on the prestrike phenomenon in single-break VCBs. However, experimental work on prestrike characteristics of double-break VCBs cannot be found in literature. This paper aims to experimentally determine the probabilistic characteristics of prestrike gaps in a double-break VCB consisting of two commercial vacuum interrupters (VIs) in series under direct current (DC) voltages. As a benchmark, single-break prestrike gaps were measured by short-circuiting one of the VIs in a double break. The experimental results show that the 50% prestrike gap d50 of each VI in a double break, which is calculated with the complementary Weibull distribution, was significantly reduced by 25% to 72.7% compared with that in a single break. Due to the voltage-sharing effect in the double-break VCB, scatters in prestrike gaps of each VI in a double break was smaller than that in a single break. However, without the sharing-voltage effect, d50 of the low-voltage side in the double break was 65% higher than that of the same VI in the single break, which could be caused by the asynchronous property of mechanical actuators, the difference of the inherent prestrike characteristics of each VI and the unequal voltage-sharing ratio of VIs.

scholarly journals Impact of Component Dispersion in DC to DC Low-Power Low-Voltage Power Converter Array

Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 917
Author(s):  
Jean-Christophe CREBIER ◽  
Theo LAMORELLE ◽  
Silvain MARACHE ◽  
Thanh Hai PHUNG ◽  
Van-Sang NGUYEN ◽  
...  
Keyword(s):  
Closed Loop ◽  
Low Voltage ◽  
Power Converter ◽  
Point Of View ◽  
Statistical Point ◽  
Loop Control ◽  
In Series ◽  
And Performance ◽  
Set Up ◽  
The Impact

The paper deals with arrays of numerous power conversion cells, associated in series and/or in parallel to build larger step up or step down direct current (DC)/DC isolated converters. The work focuses on the impact of the spread and distribution of the conversion cell characteristics on the characteristics and performance of the power converter array (PCA). Based on a characterization protocol, about 130 conversion standard cells (CSC) are characterized and classified from a statistical point of view. Three families are defined and representatives are chosen and implemented in various configurations, in open and closed loop control, to analyze the impact of their spread characteristic over the global converter, the PCA. The paper is based on an extended practical set up and protocols, all described in details. Guidelines on CSCs implementation with respect to their dispersion are provided at the end on the paper.

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