scholarly journals On the development of a novel high VSWR programmable impedance tuner

2016 ◽  
Vol 8 (4-5) ◽  
pp. 723-730
Author(s):  
Arnaud Curutchet ◽  
Anthony Ghiotto ◽  
Manuel Potéreau ◽  
Magali De Matos ◽  
Sébastien Fregonese ◽  
...  
Keyword(s):  
Standing Wave ◽  
Frequency Band ◽  
High Voltage ◽  
Characteristic Impedance ◽  
Coaxial Line ◽  
Experimental Results ◽  
Microwave Frequencies ◽  
Microwave Components ◽  
Push Forward ◽  
Impedance Tuners

Impedance tuners are key instruments used for load- and source–pull measurements. They are crucial for any active microwave components, circuits, and systems characterization and optimization. This paper reports theoretical, simulated, and experimental results related to the development of a novel programmable impedance tuner offering high-voltage standing wave ratio (VSWR). After presenting the proposed tuner principle, a fabricated prototype operating at microwave frequencies and based on a 3.5 mm coaxial line is introduced with experimental results. Depending on the targeted frequency band, different pairs of slugs, with optimized length and characteristic impedance, can be used to obtain an optimal VSWR. This first prototype allowed us to demonstrate the interest of the proposed impedance synthesis principle and to identify ways forward to further improve its performances and push forward this promising technology.

High-Temperature Dielectric Properties Measurements of Ceramics

1992 ◽  
Vol 269 ◽  
Author(s):  
Shane Bringhurst ◽  
Octavio M. Andrade ◽  
Magdy F. Iskander
Keyword(s):  
High Temperature ◽  
Dielectric Properties ◽  
Frequency Band ◽  
Perturbation Technique ◽  
Measurement Techniques ◽  
Coaxial Line ◽  
Experimental Results ◽  
Experimental Measurements ◽  
Insulating Materials ◽  
Made In

ABSTRACTThis paper dicusses experimental arrangements, describes measurement techniques and presents experimental results for hightemperature broadband dielectric properties measurements of ceramics. The cavity perturbation technique and the open-ended coaxial line method are used in these experimental measurements. The design and construction details of cavities and probes are described and representative results of measurements on zirconia and alumina samples (green and sintered) are presented. Results of measurements made on insulating materials are shown. In general measurements are made in the frequency band 1 to 10 GHz and temperatures up to 1000°C.

scholarly journals Numerical Study of Extremely Wideband-Modified Biconical Radiation Structures for Electronic Support Measures Application

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 369
Author(s):  
Chen Wu ◽  
Janaka Elangage
Keyword(s):  
Frequency Band ◽  
Numerical Study ◽  
Characteristic Impedance ◽  
Coaxial Line ◽  
Frequency Bands ◽  
Metallic Ring ◽  
Metallic Rings ◽  
Tunable Frequency ◽  
Electronic Support ◽  
Difference Time

Using the finite difference time domain (FD-TD) method, this paper studies radiation structures that can have multiple tunable frequency bands between 0.4 GHz and 4 GHz, a fixed band in [3.97, 5.36] GHz and an extremely wideband from 6.14 GHz to 68.27 GHz, where a frequency band is defined by the voltage standing wave ratio (VSWR) less than or equal to two. The base radiation structure has a modified-biconical antenna configuration, called base MBA, and is fed by a square-coaxial line with characteristic impedance close to 50 ohms. A dielectric ring and an outer dielectric cover are used between the two modified cones to enlarge the frequency band and strengthen the structure. An equal number of metallic-rings can be stacked at both circular-ends of cones in the base MBA to tune the positions of the frequency bands that are lower than 4 GHz and to alter their vertical polarization (V-pol) patterns. However, compared with those of the base MBA, these stacked metallic rings do not make significant changes to the VSWR in the [3.97, 5.36] GHz and [6.14, 28.27] GHz bands and the radiation patterns in the [6.14, 28.27] GHz band. The simulation results show that the base MBA and its metallic-ring-loaded versions all have V-pol radiation characteristics at all frequency bands and have donut-shaped omnidirectional patterns only when the wavelength is bigger than the length of the structure. When the wavelength is less than the size of the radiation structure, the donut shape is modified with ripples on the V-pol radiation pattern. Sometimes deep notches could be observed when MBAs operated at the higher end of the extremely wideband. A 0.2 mm cube was used to construct the antenna structures with the consideration of using the 3D metal/dielectric printer technology to build the antennas in the future.

Opto-mechanical modeling and experimental implementation of an FBG-based piezoelectric bimorph actuator for high voltage sensing applications

2021 ◽  
pp. 1045389X2110282
Author(s):  
Raúl E Jiménez ◽  
José P Montoya ◽  
Rodrigo Acuna Herrera
Keyword(s):  
High Voltage ◽  
Good Accuracy ◽  
Correction Term ◽  
Experimental Results ◽  
Mechanical Modeling ◽  
Piezoelectric Bimorph ◽  
Linear Strain ◽  
Voltage Sensing ◽  
Sensing Applications ◽  
Experimental Implementation

This paper proposes a highly simplified optical voltage sensor by using a piezoelectric bimorph and a Fiber Bragg Grating (FBG) that can be used for high voltage applications with a relatively good accuracy and stability. In this work the theoretical framework for the whole opto-mechanical operation of the optical sensor is detailed and compared to experimental results. In the analysis, a correction term to the electric field is derived to account for the linear strain distribution across the piezoelectric layer improving the designing equations and giving more criteria for future developments. Finally, some experimental results from a laboratory scale optical-based high voltage sensing setup are discussed, and shown to be in excellent agreement with theoretical expected behavior for different voltage magnitudes.

Subnanosecond rise time of high voltage pulses in ferrite loaded coaxial line

2008 ◽  
Author(s):  
Oleg B. Kovalchuk ◽  
Viktor O. Kutenkov ◽  
Ilya V. Romanchenko ◽  
Vladislav V. Rostov
Keyword(s):  
High Voltage ◽  
Rise Time ◽  
Coaxial Line ◽  
Voltage Pulses

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.

scholarly journals Experimental Investigation of the Propagation and Attenuation Rule of Blasting Vibration Wave Parameters Based on the Damage Accumulation Effect

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Huaibao Chu ◽  
Xiaolin Yang ◽  
Shuanjie Li ◽  
Weimin Liang
Keyword(s):  
Frequency Band ◽  
Damage Accumulation ◽  
Low Frequency ◽  
Experimental Results ◽  
Vibration Velocity ◽  
Blasting Vibration ◽  
Main Frequency ◽  
Wave Parameters ◽  
Accumulation Effect ◽  
Vibration Wave

The propagation and attenuation rule of blasting vibration wave parameters is the most important foundation of blasting vibration prediction and control. In this work, we pay more attention to the influence of the damage accumulation effect on the propagation and attenuation rule of vibration wave parameters. A blasting damage accumulation experiment was carried out, the ultrasonic wave velocity of the specimens was measured, and the damage value was calculated during the experiment. The blasting vibration wave was monitored on the surface of the specimens, and its energy was calculated by using the sym8 wavelet basis function. The experimental results showed that with the increase in the number of blasts, the damage continues to increase; however, the vibration velocity and the main frequency decrease continuously, the unfocused vibration wave energy in the zone near to the blasting source is rapidly concentrated in the low-frequency band (frequency bands 1 to 3), and the energy is further concentrated in the low-frequency band in the intermediate zone and zone far from the blasting source. There is a distortion process in which the vibration velocity and the main frequency increase slightly and the energy of the blasting vibration wave converges to the high-frequency band (the 5th band) before the sudden unstable fracture failure of the specimens. The experimental results indicate that the prediction and evaluation of blasting vibration should consider the variation rule of blasting vibration wave parameters synthetically based on the cumulative damage effect, and it is not safe to use only one fixed vibration control standard for the whole blasting operation.

scholarly journals Modified Cascaded Z-Source High Step-Up Boost Converter

Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1932
Author(s):  
Navid Salehi ◽  
Herminio Martínez-García ◽  
Guillermo Velasco-Quesada
Keyword(s):  
High Voltage ◽  
Boost Converter ◽  
Experimental Results ◽  
Input Current ◽  
Voltage Gain ◽  
Low Input ◽  
High Voltage Gain ◽  
Voltage Stress ◽  
Photovoltaic Applications ◽  
Current Ripple

To improve the voltage gain of step-up converters, the cascaded technique is considered as a possible solution in this paper. By considering the concept of cascading two Z-source networks in a conventional boost converter, the proposed topology takes the advantages of both impedance source and cascaded converters. By applying some modifications, the proposed converter provides high voltage gain while the voltage stress of the switch and diodes is still low. Moreover, the low input current ripple of the converter makes it absolutely appropriate for photovoltaic applications in expanding the lifetime of PV panels. After analyzing the operation principles of the proposed converter, we present the simulation and experimental results of a 100 W prototype to verify the proposed converter performance.

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