scholarly journals Passive Microwave Component Design Using Inverse Scattering: Theory and Applications

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Israel Arnedo ◽  
Iván Arregui ◽  
Magdalena Chudzik ◽  
Fernando Teberio ◽  
Aintzane Lujambio ◽  
...  
Keyword(s):  
Frequency Response ◽  
Inverse Scattering ◽  
Filter Design ◽  
Pulse Generation ◽  
Design Tool ◽  
Passive Microwave ◽  
Synthesis Methods ◽  
Component Design ◽  
Starting Point ◽  
Compact Design

We briefly review different synthesis techniques for the design of passive microwave components with arbitrary frequency response, developed by our group during the last decade. We provide the theoretical foundations based on inverse scattering and coupled-mode theory as well as several applications where the devices designed following those techniques have been successfully tested. The main characteristics of these synthesis methods are as follows. (a) They are direct, because it is not necessary to use lumped-element circuit models; just the target frequency response is the starting point. (b) They are exact, as there is neither spurious bands nor degradation in the frequency response; hence, there is no bandwidth limitation. (c) They are flexible, because they are valid for any causal, stable, and passive transfer function; only inviolable physical principles must be guaranteed. A myriad of examples has been presented by our group in many different technologies for very relevant applications such as harmonic control of amplifiers, directional coupler with enhanced directivity and coupling, transmission-type dispersive delay lines for phase engineering, compact design of high-power spurious free low-pass waveguide filters for satellite payloads, pulse shapers for advanced UWB radar and communications and for novel breast cancer detection systems, transmission-typeNth-order differentiators for tunable pulse generation, and a robust filter design tool.

Response Prediction and Dynamic Substructuring for Coupled Structures in the Frequency Domain

2020 ◽  
Vol 36 (6) ◽  
pp. 867-879
Author(s):  
X. H. Liao ◽  
W. F. Wu ◽  
H. D. Meng ◽  
J. B. Zhao
Keyword(s):  
Frequency Response ◽  
Response Function ◽  
Frequency Response Function ◽  
Dynamic Properties ◽  
Main Idea ◽  
Prediction Method ◽  
Response Prediction ◽  
Synthesis Methods ◽  
Dynamic Substructuring ◽  
Coupled Structures

ABSTRACTTo evaluate the dynamic properties of a coupled structure based on the dynamic properties of its substructures, this paper investigates the dynamic substructuring issue from the perspective of response prediction. The main idea is that the connecting forces at the interface of substructures can be expressed by the unknown coupled structural responses, and the responses can be solved rather easily. Not only rigidly coupled structures but also resiliently coupled structures are investigated. In order to further comprehend and visualize the nature of coupling problems, the Neumann series expansion for a matrix describing the relation between the coupled and uncoupled substructures is also introduced in this paper. Compared with existing response prediction methods, the proposed method does not have to measure any forces, which makes it easier to apply than the others. Clearly, the frequency response function matrix of coupled structures can be derived directly based on the response prediction method. Compared with existing frequency response function synthesis methods, it is more straightforward and comprehensible. Through demonstration of two examples, it is concluded that the proposed method can deal with structural coupling problems very well.

COMPACT MICROSTRIP BAND-PASS FILTER FOR EMI REDUCTION

2015 ◽  
Vol 77 (12) ◽  
Author(s):  
Kabir Ibrahim Jahun ◽  
Hussein Mohamed Hagi Hassan Abdirahman Mohamud Shire ◽  
Ali Orozi Sougui ◽  
S. H. Dahlan
Keyword(s):  
Filter Design ◽  
Stop Band ◽  
Band Pass Filter ◽  
Defected Ground Structure ◽  
Coupled Line ◽  
Pass Filter ◽  
Filter Structure ◽  
Coupled Lines ◽  
Band Pass ◽  
Compact Design

Compact microstrip band-pass filter design using parallel coupled lines is presented in this paper. The microstrip lines are calculated and constructed using CST studio with two input and output ports of the filter structure are printed over Defected Ground Structure (DGS).The proposed symmetrical structure offers a simple and compact design while exhibiting an improved stop-band characteristics in comparison to conventional coupled microstrip line filter structure. The simulation and measurements of 2GHz prototype band pass filter are presented. The measured result agrees well with the simulation data. Compared with conventional parallel coupled line band pass filter, the second, third and fourth spurious responses are suppressed; in addition, the size of the prototype filter circuit is reduced up to 20.8%.  

Experimental Validation of a Nonlinear Model Calibration Method Based on Multiharmonic Frequency Responses

2017 ◽  
Vol 12 (4) ◽  
Author(s):  
Yousheng Chen ◽  
Andreas Linderholt ◽  
Thomas J. S. Abrahamsson
Keyword(s):  
Steady State ◽  
Frequency Response ◽  
Test Data ◽  
Nonlinear Model ◽  
Model Calibration ◽  
Experimental Validation ◽  
Calibration Method ◽  
Model Parameters ◽  
Response Data ◽  
Starting Point

Correlation and calibration using test data are natural ingredients in the process of validating computational models. Model calibration for the important subclass of nonlinear systems which consists of structures dominated by linear behavior with the presence of local nonlinear effects is studied in this work. The experimental validation of a nonlinear model calibration method is conducted using a replica of the École Centrale de Lyon (ECL) nonlinear benchmark test setup. The calibration method is based on the selection of uncertain model parameters and the data that form the calibration metric together with an efficient optimization routine. The parameterization is chosen so that the expected covariances of the parameter estimates are made small. To obtain informative data, the excitation force is designed to be multisinusoidal and the resulting steady-state multiharmonic frequency response data are measured. To shorten the optimization time, plausible starting seed candidates are selected using the Latin hypercube sampling method. The candidate parameter set giving the smallest deviation to the test data is used as a starting point for an iterative search for a calibration solution. The model calibration is conducted by minimizing the deviations between the measured steady-state multiharmonic frequency response data and the analytical counterparts that are calculated using the multiharmonic balance method. The resulting calibrated model's output corresponds well with the measured responses.

scholarly journals Initial User Experience With an Artificial Intelligence Program for the Preliminary Design of Centrifugal Compressors

1987 ◽  
Author(s):  
Carol J. Russo ◽  
Dennis J. Nicklaus ◽  
Siu S. Tong
Keyword(s):  
Artificial Intelligence ◽  
Design Tool ◽  
Parameter Study ◽  
Balance Performance ◽  
New Approach ◽  
Trade Offs ◽  
Component Design ◽  
Small Set ◽  
Development Risks ◽  
Artificial Intelligence Program

A new approach is evaluated for the design of turbomachinery components using existing analysis codes coupled to a generic Artificial Intelligence (AI) software framework called ENGINEOUS. This AI framework uses intelligent search techniques with a small set of basic component design rules to iterate to an optimized solution and to quantify parameter trade-offs. Initial experience with ENGINEOUS indicates that it is a powerful design tool which quickly identifies non-obvious solutions balanced for conflicting multiple goals in a small number of iterations which vary linearly with the number of variables. The solution path and driving logic are easily visible to the designer and a parameter study option can rapidly quantify potential design trade-offs which together allow a critique of the selected design to balance performance against development risks. Because this AI design approach fosters intelligent interface with the designer and is generic, the potential application areas and productivity benefits appear enormous.

scholarly journals Real-time temperature calculation and temperature prediction of wet multi-plate clutches

2021 ◽  
Author(s):  
D. Groetsch ◽  
K. Voelkel ◽  
H. Pflaum ◽  
K. Stahl
Keyword(s):  
Real Time ◽  
Operation Mode ◽  
Time Estimation ◽  
Design Tool ◽  
Operating Conditions ◽  
Temperature Prediction ◽  
Temperature Calculation ◽  
Component Design ◽  
Component Test ◽  
Real Time Estimation

AbstractMany applications of wet multi-plate clutches are within safety-critical areas since malfunction or failure of the clutch is often equivalent to “loss of drive”.The main criterion for the estimation of damage and endurance of wet multi-plate clutches is the temperature on the friction interface. Owing to the thin, rotating geometry of the plates, determination of relevant temperatures in operation mode is almost impossible. State of the art is that there is no general applicable model for real-time estimation of clutch temperatures during operation.This contribution presents a validated parametric real-time temperature model that is applicable to various use cases and operating conditions. The model enables the calculation of the actual clutch temperature during operation and the prediction of temperature for future shifting operations.The model is validated by comparing temperature measurements from a component test rig and from the KUPSIM thermal clutch design tool with the developed real-time temperature calculation. The validity of the model for serial parts from industry and automotive applications under various load cases (clutch mode, continuous slip, non-steady slip) is demonstrated. The deviation between measurement and calculation are typically very small (< 5 K). The temperature prediction allows a highly accurate (deviations typically < 5 K) conservative prediction of the thermal load for future shifting operations.The model can thus contribute to the increase of operational safety of wet multi-plate clutches while at the same time facilitating optimal component design by reducing thermal over-dimensioning of clutches.

scholarly journals Design, Optimization and Analysis of Supersonic Radial Turbines

2019 ◽  
Author(s):  
Lukas Benjamin Inhestern ◽  
James Braun ◽  
Guillermo Paniagua ◽  
José Ramón Serrano Cruz
Keyword(s):  
High Performance ◽  
Ad Hoc ◽  
Three Dimensional ◽  
Critical Factor ◽  
Design Tool ◽  
Navier Stokes ◽  
Design Parameters ◽  
Design Variables ◽  
Compact Design ◽  
Radial Outflow

Abstract New compact engine architectures such as pressure gain combustion require ad-hoc turbomachinery to ensure an adequate range of operation with high performance. A critical factor for supersonic turbines is to ensure the starting of the flow passages, which limits the flow turning and airfoil thickness. Radial outflow turbines inherently increase the cross section along the flow path, which holds great potential for high turning of supersonic flow with a low stage number and guarantees a compact design. First the preliminary design space is described. Afterwards a differential evolution multi-objective optimization with 12 geometrical design parameters is deducted. With the design tool AutoBlade 10.1, 768 geometries were generated and hub, shroud, and blade camber line were designed by means of Bezier curves. Outlet radius, passage height, and axial location of the outlet were design variables as well. Structured meshes with around 3.7 million cells per passage were generated. Steady three dimensional Reynolds averaged Navier Stokes (RANS) simulations, enclosed by the k-omega SST turbulence model were solved by the commercial solver CFD++. The geometry was optimized towards low entropy and high power output. To prove the functionality of the new turbine concept and optimization, a full wheel unsteady RANS simulation of the optimized geometry exposed to a nozzled rotating detonation combustor (RDC) has been performed and the advantageous flow patterns of the optimization were also observed during transient operation.

scholarly journals Towards the numerical ground-borne vibrations predictive models as a design tool for railway lines: A starting point THE

2021 ◽  
Vol 58 ◽  
pp. 363-369
Author(s):  
Andrés García Moreno ◽  
Juan Jesús Ruiz Aguilar ◽  
José Antonio Moscoso López
Keyword(s):  
Predictive Models ◽  
Design Tool ◽  
Starting Point

Driver Filter Design for Software-Implemented Loudspeaker Crossovers

2015 ◽  
Vol 39 (4) ◽  
pp. 591-597
Author(s):  
Yao Shu-Nung
Keyword(s):  
High Frequency ◽  
Filter Design ◽  
Computational Cost ◽  
Pass Band ◽  
Listening Tests ◽  
Integration Architecture ◽  
Low Pass ◽  
Band Pass ◽  
Intuitive Idea ◽  
Compact Design

Abstract A hybrid method is presented for the integration of low-, mid-, and high-frequency driver filters in loud-speaker crossovers. The Pascal matrix is exploited to calculate denominators; the locations of minimum values in frequency magnitude responses are associated with the forms of numerators; the maximum values are used to compute gain factors. The forms of the resulting filters are based on the physical meanings of low-pass, band-pass, and high-pass filters, an intuitive idea which is easy to be understood. Moreover, each coefficient is believed to be simply calculated, an advantage which keeps the software-implemented crossover running smoothly even if crossover frequencies are being changed in real time. This characteristic allows users to efficiently adjust the bandwidths of the driver filters by subjective listening tests if objective measurements of loudspeaker parameters are unavailable. Instead of designing separate structures for a low-, mid-, and high-frequency driver filter, by using the proposed techniques we can implement one structure which merges three types of digital filters. Not only does the integration architecture operate with low computational cost, but its size is also compact. Design examples are included to illustrate the effectiveness of the presented methodology

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