Product category:
Design and Development Software
News Release from: Vector Fields | Subject: Concerto and Quickwave
Edited by the Electronicstalk Editorial
Team on 25 January 2005
Virtual prototyping for RF and microwave
devices
A new software package extends the concept of "virtual prototyping" to RF and microwave devices.
A new software package from Vector Fields extends the concept of "virtual prototyping" to RF and microwave devices The package allows designers to optimise parameters at which earlier microwave engineers could only guess and await for field trials to illuminate
This article was originally published on Electronicstalk on 30 Jul 2003 at 8.00am (UK)
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Software orchestrates microwave modelling
Vector Fields has upgraded its Concerto software for three-dimensional analysis and design of microwave components such as antennas, waveguides, microstrips and microwave heating etc.
Electromagnetic simulator gains thermal module
The rate of development of the Opera suite of simulation software for electromagnetic analysis has increased recently with the strengthened team at Vector Field's Oxford headquarters.
Not only does this later software suite provide engineers with the ability to establish fundamentals of a new project before building prototypes, it also allows assessment of the "what if" scenario.
Radical designs can be created and tested at a fraction of the cost of traditional methods.
In some applications, this saving of time and effort can be dramatic with one software user working with Vector Field's packages managing a reduction in time spent from a full person-year per prototype using traditional methods, to one designer analysing 60 designs in a single month.
Further reading
Simulation optimises design of antenna array
A circular polarised patch antenna has recently been simulated using software from Vector Fields, and the simulation considerably reduced the development time.
Simulation helps provide cost-effective screening
Electromagnetic simulation has substantially reduced the cost of the protective shields surrounding magnetic resonance imaging (MRI) suites at one Chicago hospital.
Software suite gains method-of-moments analysis
Vector Fields has signed an agreement to market the Clasp software developed by Abingdon based Culham Electromagnetics and Lightning.
The ability of currently available software is exemplified by Concerto from Vector Fields - a fully three dimensional high frequency modelling package which uses the conformal finite difference time domain method with an advanced user interface and state of the art numerical algorithms.
It can model all microwave devices including patch, slot, wire or horn antennas, waveguides, couplers, filters etc.
Models are created using a 3D geometric modeller, permitting simple or complex shapes to be created quickly and efficiently, or models can be built using a library of predefined, parameterised objects.
From simple primitives (sphere, torus, block, prism/pyramid and cylinder/cone), Boolean operations (union, subtract, intersect, trim, cutaway) are used to build more complex structures.
Bodies can be transformed and faces swept.
Other functions are included for blending, chamfering, twisting, lofting and "morphing".
There is a facility for users to create their own library items.
In addition thin sheets and wires can be embedded within the finite difference grid.
The Quickwave simulator is based on the finite difference time domain (FDTD) technique, and uses the unique conforming meshing technology to ensure complex geometries are easily and efficiently modelled.
Conforming elements allow material boundaries to intersect with finite difference cells, so that cells can contain more than one material.
This technique used in Quickwave is unique in that it requires no extra terms to be added (no increase in memory) and the time step does not need to be reduced (no increase in solution time).
The results of the simulation can be viewed dynamically in the multiwindow simulator in a number of ways.
Enhanced techniques unique to Quickwave allow accurate S-parameter extraction, including below cutoff, and features to reduce errors.
Any number of S-parameters can be displayed on the same graph, including previously saved data for ease of comparison of changes.
The fields can be displayed on planes throughout the model.
In addition, the fields and surface currents can be shown on the surface of the model itself.
All the data required for the analysis are defined in the modeller, which then launches the Quickwave analysis.
The data include global settings (eg units), material properties, and boundary conditions (including ports).
Efficient absorbing boundary conditions ensure the boundaries do not generate spurious reflections (both PML and high order ABC are used).
Symmetry condition can be used to reduce the size of an analysis by only requiring part of the complete structure to be analysed.
The expert mesher within the modeller uses the frequency and material properties to set initial cell sizes correctly.
The relevant geometric features are captured using the mesher, enabling special facilities within the analysis to be effective (for example a feature to represent field singularities near metallic corners accurately).
Users can override the automatic settings if desired.
Advanced features in Concerto permit a rapid initial analysis of axi-symmetric geometries and higher order axi-periodic modes using the 2D Quickwave module.
Although only a 2D section is modelled, the full vector equations are solved.
Also for thermally sensitive designs, as thermal properties of the materials can be defined the temperature rise due to microwave heating can be predicted accurately.
For high Q devices, the use of the QProny module can reduce the solution time by a factor of 10 or more.
By filtering out the oscillations in the frequency response, an accurate prediction of the S parameters can be obtained without waiting for all the energy to dissipate in the system.
Applications in industry, science and education are varied and include telecommunications, microwave ovens, defence, microwave chemistry, space and atmosphere research, food processing and electromagnetic impact on biological tissues.
For example, thin wires can be used for antenna modelling, and with near-to-far field transformation, 2D and 3D radiation plots can be produced.
The complex geometry of horn antennas can be modelled accurately using the conforming mesh.
Patch antennas are efficiently modelled by using infinitely thin metal layers.
Resonant frequencies of cavity structures can be determined including lossy walls and lossy loads.
For each resonant mode, the Q-factors can be computed, and the modal shape interrogated.
For waveguide components, enhanced S-paramater calculations ensure the highest level of accuracy, including below cutoff.
Multimode analyses can easily be performed.
For a very demanding application, such as filters, the advanced techniques within Concerto are required to give accurate solutions.
The thin sheet models can be used for planar filters, and local grid refinement is brought into play where extra precision is required.
With the unique QProny module, the analysis time can be reduced significantly without loss of accuracy.
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