RF breakdown in “cold” slow wave structures operating at travelling wave mode of TM01

2018 ◽  
Vol 25 (1) ◽  
pp. 013101
Keyword(s):  
Slow Wave ◽  
Travelling Wave ◽  
Wave Mode ◽  
Rf Breakdown

Comparison of the Influence Coefficient Method and Travelling Wave Mode Approach for the Calculation of Aerodynamic Damping of Centrifugal Compressors and Axial Turbines

2017 ◽  
Author(s):  
K. Vogel ◽  
A. D. Naidu ◽  
M. Fischer
Keyword(s):  
Centrifugal Compressor ◽  
Travelling Wave ◽  
Wave Mode ◽  
Forced Response ◽  
Computational Time ◽  
Influence Coefficient ◽  
Average Deviation ◽  
Aerodynamic Damping ◽  
Influence Coefficients ◽  
Periodic Boundaries

The prediction of aerodynamic damping is a key step towards high fidelity forced response calculations. Without the knowledge of absolute damping values, the resulting stresses from forced response calculations are often afflicted with large uncertainties. In addition, with the knowledge of the aerodynamic damping the aeroelastic contribution to mistuning can be considered. The first section of this paper compares two methods of one-way-coupled aerodynamic damping computations on an axial turbine. Those methods are: the aerodynamic influence coefficient, and the travelling wave mode method. Excellent agreement between the two methods is found with significant differences in required computational time. The average deviation between all methods for the transonic turbine is 4%. Additionally, the use of transient blade row methods with phase lagged periodic boundaries are investigated and the influence of periodic boundaries on the aerodynamic influence coefficients are assessed. A total of 23 out of 33 passages are needed to remove all influence from the periodic boundaries for the present configuration. The second part of the paper presents the aerodynamic damping calculations for a centrifugal compressor. Simulations are predominantly performed using the aerodynamic influence coefficient approach. The influence of the periodic boundaries and the recirculation channel is investigated. All simulations are performed on a modern turbocharger turbine and centrifugal compressor using ANSYS CFX V17.0 with an inhouse pre- and post-processing procedure at ABB Turbocharging. The comparison to experimental results concludes the paper.

A Review of Slow Wave Structure of Travelling Wave Antenna using Waveguide

2016 ◽  
Vol 3 (1) ◽  
pp. 1-5
Author(s):  
Sakshi Jindal ◽  
◽  
Kritika Khanna ◽  
Brajlata Chauhan ◽  
Rashmi Choudhary ◽  
...  
Keyword(s):  
Slow Wave ◽  
Wave Structure ◽  
Travelling Wave ◽  
Slow Wave Structure ◽  
Wave Antenna

Slow-Wave Mode Rectification on Non-Linear Microstrip

1997 ◽  
Vol 32 (4) ◽  
pp. 223-232
Author(s):  
L. E. Winkelmann ◽  
T. K. Ishii
Keyword(s):  
Slow Wave ◽  
Wave Mode ◽  
Non Linear

scholarly journals Radiating structure based on inverted dielectric waveguide with additional elements

2018 ◽  
Keyword(s):  
Dielectric Waveguide ◽  
Electromagnetic Compatibility ◽  
Short Circuit ◽  
Near Field ◽  
Travelling Wave ◽  
Wave Mode ◽  
Field Structure ◽  
Problem Solution ◽  
Dielectric Structure ◽  
Dielectric Plate

Background. Creation of effective radiating structures operating in millimeter range is one of the important directions in modern microwave technology. The use of different hybrid metal-dielectric structures for this range becomes increasingly significant because of possible occurrence of certain physical effects, which are impossible in standard dielectric waveguides and structures on their basis.Objectives. Experimentally investigate the main electrodynamic characteristics of a hybrid metal-dielectric structure, including the ways of excitation and matching with external circuits, energy characteristics.Materials and methods. Hybrid metal-dielectric structure is based on inverted dielectric waveguide, which contains metallized base, dielectric rod made of polystyrene and additional dielectric plate made of glass ceramics. Auxiliary radiating elements in the form of rods of finite length with metallized face are located at certain period on the additional dielectric plate. The near-field structure measurements are carried out through the moving probe method. The isoline method has been used for field structure visualization.Results. The construction of a hybrid radiating structure based on inverted dielectric waveguide with periodically located additional rectangular dielectric rods. The radiation patterns have been measured in H-plane in two modes: short-circuit mode and travelling wave mode. Based on near-field structure measurements, the behavior of the electromagnetic wave propagating in the waveguiding rod and the degree of excitation of the metallized parts of additional structure elements are obtained. The degree of excitation of a surface wave and the possibility of its radiation are obtained. Based on this data, shielding elements insertion possibility and electromagnetic compatibility problem solution can be estimated. Conclusions: The research has revealed possible effective radiation in travelling wave mode with acceptable direct loss, provided by proposed hybrid metal-dielectric structure. Moreover, the structure can provide an acceptable level of matching with external circuits. The possibility of radiated fields with specified characteristics formation in the short circuit and traveling wave modes is demonstrated.

scholarly journals Equivalent circuit model of through-silicon-via in slow wave mode

2017 ◽  
Vol 14 (22) ◽  
pp. 20171025-20171025 ◽  
Author(s):  
Fengjuan Wang ◽  
Gang Wang ◽  
Ningmei Yu
Keyword(s):  
Equivalent Circuit ◽  
Slow Wave ◽  
Equivalent Circuit Model ◽  
Wave Mode ◽  
Circuit Model ◽  
Through Silicon Via
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