Wednesday, June 13, 2018

New whitepaper: Designing a Compact Ridged Waveguide Filter

Designing a Compact Ridged Waveguide Filter

Multi-mode cavity filters offer high power handling and good performance as a compact device. Such filters are complex and sensitive to changes in the structure, meaning that their design can be time-consuming or even impossible with conventional methods. This article shows how the CST® filter synthesis tool Filter Designer 3D, part of the simulation software CST STUDIO SUITE®, can be used to design and tune a multi-mode compact ridged waveguide filter to meet stringent specifications.

The proliferation of mobile communication systems and protocols mean frequency spectrum
utilization is increasingly restricted – realizing the stringent channel specifications require high-performance band-pass filters. Satellite systems in particular are very exact in frequency, power, size and weight requirements: the filter response should produce steep cut-off to avoid channel interference and adhere to different standards, but size and space are typically restricted. Cavity filters are typically the preferred choice due to their power handling capabilities, but they are often bulky and heavy. Multi-mode cavity filters are therefore an attractive alternative. They use a number of modes in a single cavity, which significantly reduces the overall size. They also allow cross-couplings between cavities for a better filter response, which is not always possible for single mode resonators due to physical restrictions.

There are several simulation techniques that can be used in the tuning process of coupled-resonator filters. One traditional approach is to sequentially build up the filter by adding only one resonator at a time, while the group delay of the reflected signal is used as the figure of merit for the optimization. Another approach is to apply the inverse chirp Z-transformation to the reflected signal and from the transient response identify the individual detuned resonators and couplings. It is also possible to add additional ports to the full-wave simulation model and connect lumped components in a coupled schematic for space mapping[. All of these techniques typically involve using an equivalent circuit as a surrogate model where intermediate results can quickly be obtained as a reference during the process.

Friday, April 20, 2018

Announcing the 2017 YEP Award winners

The Yes! Education Program (YEP) Award, an initiative run by our partners AET Japan, grants an extended one-year license to universities that use CST software, in order to assist their research projects.

We spoke to this year's winners about their work and their experience with CST STUDIO SUITE the winners came from the National Defense Academy and the University of Yamanashi.

"A Linear Array Antenna of Microstrip Patch Antennas Fed by the Open-End of Coplanar Waveguides" by Toshihisa Kamei, Hiromi Shima, Syotaro Fukuda, Seishiro Ishii of the National Defense Academy 

Dr. Toshihisa Kamei
"It is our great pleasure that our recent paper [*] has been honored with the YEP Award. In this paper, we presented a 4-element linear array antenna using four 20 GHz band microstrip patch antennas. The signal is fed to the patch antennas from open-end coplanar waveguides without contact. We investigated factors related to the design of linear patch antenna arrays. Our group is working on communication, meteor burst communication systems, fundamental and
applied research of radio wave absorbers in the millimeter wave and microwave band from MHz to THz.
Our lab has been using CST for over 10 years. Based on the direct calculation along with realistic excitation ports and probes, we are able to model and investigate any novel structures on CST. CST STUDIO SUITE also serves as the best tool for our students to learn Maxwell’s equations and a common language. We believe that CST Software is very convenient for university education and research and allows quick testing of new and difficult ideas at a low cost.' - Dr. Toshihisa Kamei

[*] Toshihisa Kamei, Hiromi Shima, Syotaro fukuda, Seishiro Ishii

A Linear Array Antenna of Microstrip Patch Antennas Fed by the Open-End of Coplanar Waveguides, Pub. Date: April 14, 2017DOI:10.4236/wer.2017.820

“A Novel REBCO Wire Structure That Improves Coil Quality Factor in MHz Range and its Effect on Wireless Power Transfer Systems” by N. Sekiya and Y. Monjugawa of the University of Yamanashi

Dr. Sekiya's lab students
"We would be greatly honored to receive the CST YEP AWARD2017 for our published paper [*]. We also appreciate the cooperation between our lab students and CST support.

In this paper, we described the development and application of superconducting wire which realizes low losses at high frequencies. Conventional superconducting wire has no loss in direct current, but a high loss at high frequencies. That is why the application in this field has not developed. To solve this problem, we propose a new superconducting wire structure and investigate its effect through simulation and experimental verification.

Superconducting wire requires a substantial amount of time to calculate because they have a multilayer structure. As our lab had the small number of staff, we needed to proceed our research effectively. Under these circumstances, CST STUDIO SUITE helped us to proceed our research more efficiently. We will continue to use CST STUDIO SUITE to create innovative research." -Dr. Naoto Sekiya
Dr. Naoto Sekiya

[*] N. Sekiya and Y. Monjugawa, “A Novel REBCO Wire Structure That Improves Coil Quality Factor in MHz Range and its Effect on Wireless Power Transfer Systems”
Learn more about our academic programs here. 

Thursday, April 19, 2018

Featured whitepaper: Optical Materials in CST STUDIO SUITE

CST recently published a new whitepaper about simulating special optical materials in integrated components with CST STUDIO SUITE®. 

For many optical applications, materials are needed with anisotropic or nonlinear
properties. Two important examples of such properties are birefringence and dichroism.
Such materials exhibit different refractive indices and attenuation for orthogonal optical
polarization states. They are used to alter the polarization state of the light for example in
polarizers or polarization converters. A special case of a polarization dependent material
property is magneto-optical activity. Magneto-optical active materials can also be used to
alter the polarization state, but more importantly they can be used to build non-reciprocal
components like isolators. Further, the optical properties can not only depend on the state of
polarization but also on the electric field amplitude of the light wave. The optical properties
can depend on the second, third power or even higher powers of the electric field. Here,
the effects and applications are vast – amplification, frequency conversion, and all-optical
switching to name but a few.

To learn more, read "Optical Materials in CST STUDIO SUITE"

Wednesday, April 11, 2018

Submit to the CST University Publication Award

The deadline to submit your work for the CST University Publication Award is April 15, 2018. To honor the work that is done using CST STUDIO SUITE® at institutions around the world, we present the CST University Publication Award. Past awardees have pioneered breakthroughs in a wide range of fields. The winners' respective university institutes will recieve upgraded licenses for one year.

We recently published an interview with one of the 2017 winners about their breakthrough in filter design for satellite communications using CST STUDIO SUITE®You can see all of last year's winners here: 2017 University Publication Award Winners

Work published April 1, 2017 - March 31, 2018 can be submitted for our University Publication Award. The submission must be in English and should also state the place of publication. Only one paper per candidate will be considered so please limit your submissions to one paper.

Friday, April 6, 2018

NVIDIA Quadro GPU acceleration in CST STUDIO SUITE®

The high memory bandwidth and parallel processing abilities of GPU cards mean that GPU computing can provide significant simulation speed advantages over conventional CPU computing.  A series of comparative analyses were carried out to test the performance of NVIDIA’s Quadro GP100 and the brand new GV100 device, pictured below in Figure 1. These tests were performed using various models which represent typical applications that are simulated in the CST STUDIO SUITE® Time-Domain Solver.

Figure 1 - The NVIDIA Quadro GV100 features 5120 CUDA cores, 32GB of HBM2 memory, 7.4 TFLOPs double precision performance and a remarkable 900GB/s memory bandwidth, making it the fastest GPU device for simulation acceleration.

An initial study was done to compare the Quadro GP100 and Quadro GV100 against a high-end CPU model of the Intel Xeon Broadwell family. The CPU vs. GPU performance in Figure 2 shows that the NVIDIA Quadro devices can provide a significant speed-up to the Time-Domain Solver Loop*. On average, the latest GV100 model is shown to perform about 8 times faster than a high-end CPU; the performance of the GP100 model is not too far behind with an average speed-up factor around 7.

Figure 2  - The above plot represents the solver loop speed-up factor due to GPU computing, in reference to Dual Intel Xeon E5-2643 v4 CPUs with 12 physical cores, 3.4GHz clock, DDR4 2400MHz memory modules, on a Windows Server 2012 R2 system.

In another test, a direct comparison of the GP100 vs. GV100 was performed. The benchmark results shown in Figure 3 illustrate the GV100 performs about 20% faster than the GP100 device. This is in-line with what is expected, since the solver speed-up tends to be proportional to the difference in memory bandwidth of the GPU devices. The new Quadro GV100 device has an impressive memory bandwidth specification of 900GB/s vs. the GP100 at 732GB/s.

Figure 3 - The above plot represents the Solver Loop percentage speed-up (%) provided by the Quadro GV100 in reference to the Quadro GP100.

Along with high memory bandwidth and parallelization capabilities, NVIDIA Quadro GPU devices have many additional noteworthy features. For instance, select Quadro cards can be utilized for the CST STUDIO SUITE double-precision solvers due to their powerful performance capabilities in this aspect. The Quadro GP100 and GV100 cards have fast double-precision performance at 5.2TFLOPs and 7.4TFLOPS respectively. The new Quadro GV100 also provides a significant increase in GPU RAM at 32GB making it very suitable for larger and more demanding tasks, which have not been possible for single GPU devices thus far.

In parallel to their computational acceleration capabilities, Quadro series GPU cards can be utilized for their accelerated graphics capabilities; this means there is no requirement for an additional adapter. Quadro cards are specifically dedicated to CAD/CAE applications and well tested with CST STUDIO SUITE, making them the recommended option for display. They are also a particularly interesting option for those who are interested in a GPU dedicated for a workstation over a server-class system. Since these devices are actively cooled, they can be installed into a workstation chassis, which tends to be a more cost efficient option for simulations which can be solved within the resources of a single system.

NVIDIA just announced the release of the NVIDIA Quadro GV100 at the end of Q1 in 2018. This device is scheduled to be supported in CST STUDIO SUITE 2018 Service Pack 4 for the Time Domain solver. Full support of the GV100 for all GPU-empowered solvers will become available in the next major release. GPU-empowered solvers consist of: Transient FIT & TLM, Particle-in-Cell, Asymptotic, Integral-Equation, Multilayer and Conjugate Heat Transfer solvers. The NVIDIA Quadro GP100 device, which was also used in this study, has been fully supported since CST STUDIO SUITE 2017 Service Pack 2.

*Note that the solver loop time is not a representation of the total simulation time. The solver loop is the main, and most compute intensive phase of a time-domain simulation. The solver is the only phase of the simulation which takes advantage of GPU computation.

 Melissa Reis 
 Application Engineer
 CST of America

Friday, March 16, 2018

Success story: Drayson Technologies Develops Innovative Energy Harvesting Technology with CST STUDIO SUITE

The CleanSpace Tag monitors air pollution and includes
Freevolt RF Energy Harvesting technology.
When Drayson Technologies were working on a compact smart sensor for monitoring air pollution incorporating Freevolt™ RF energy harvesting, Drayson's proprietary wireless charging technology, they looked to CST STUDIO SUITE® to help solve a tough electromagnetic challenge. 

The challenge: recharge the battery of an IOT sensor device. What resulted was a device that can harvest RF energy when sufficient RF power density is available. Check out the success story on our website for all the details.

“CST offers Complete Technology for simulation, with all its different solvers in one user interface. This meant that we were able to use the best solver for each application: for example, the Time Domain Solver for high-frequency simulations such as designing CleanSpace tag or the Bluetooth antenna, but easily transfer to the Frequency Domain Solver for low-frequency simulations of inductive power transfer. GPU acceleration made it possible to simulate the entire tag efficiently, speeding up simulation time and saving money.” 
-Drayson Technologies 

Read the full success story here


Wednesday, March 14, 2018

A breakthrough in filter design for satellite communications using CST STUDIO SUITE®

In December, we announced the winners of our CST University Publication Award. Every year, we select three papers and one short paper to honor and we are excited to share some of the details behind the winning research. We spoke to Dr. Miguel Laso to learn more about his team's award winning paper, “Chirping Techniques to Maximize the Power-Handling Capability of Harmonic Waveguide Low-Pass Filters.”

CST: What is the challenge that this new filter method addresses? 

Dr. Laso: The filter in this paper is the result of a multi-year collaboration between TESAT Spacecom GmbH and the Microwave Components Group at UPNA in the framework of several contracts and ESA projects. TESAT and UPNA have successfully developed a new standard of  output lowpass filter for the communications satellite payload, which withstands the combined power of all the satellite channels and cleans all the channel signals at the same time from spurious responses. This avoids the use of many individual low-pass filters, one per channel, as it is usually done now. In this paper, we surpassed our previous results, getting a filter to handle more than 100 kW, while the equivalent classical waffle-iron filter handles only 0.15 kW (!!!) before the multipactor effect appears and ruins communication.

How does this chirping technique help engineers improve their filter designs? 

Currently, although very good high-power analysis tools such as SPARK3D or CST PARTICLE STUDIO® exist, the space industry usually conducts also a costly testing campaign of the satellite parts before they are launched into space to check that everything works fine. The European Cooperation for Space Standardization (ECSS) - Multipaction design and test- is the document that the industry uses to conduct such testing campaigns. Getting such high-power handling capability, such as 100 kW in an analysis, theoretically avoids the use of this “just-in-case” testing to check whether the filter will withstand the conditions in a real working situation in space. This saves a lot of time and budget. According to the current ECSS document, the filter in the paper should handle at least 70 kW in simulation for testing to be considered unnecessary. We easily get more than 100 kW.

EM fields inside the filter using CST STUDIO SUITE. Image courtesy of Dr. Miguel Laso.

How did you use FEST3D in your research project? 

FEST3D is the ideal tool to simulate such kind of devices based on the concatenation of waveguide sections, and we can obtain the S-parameters of the filter very quickly and reliably. FEST3D also allows us to optimize the device very easily. Finally, FEST3D is also used to check the filter behavior for multimode excitation.

How did you use CST STUDIO SUITE®? 

In the paper, CST MICROWAVE STUDIO® (CST MWS), part of CST STUDIO SUITE®, is used to see the fields inside the filter. This allows us to adjust several of the most important filter parameters, such as the minimum mechanical gap, the waveguide length between the filter elements, and the length of the elements themselves, to maximize the filter power-handling capability. The power-handling was checked with SPARK3D, where we used the fields previously calculated. We also make use of CST MWS to include in the design phenomena such as the milling rounding, wall tilting, and several other imperfections that we have in the real world when the part is milled at the workshop. CST STUDIO SUITE® has also been used by our research group to simulate the frequency response of passive devices with unconventional non-step-shaped profiles, such as smooth or continuous profiles, a flagship of our research outcomes and papers for many years.

More generally, has the CST academic license and the CST University Publication Award helped your team? 
A lot, not only to simulate the sometimes “strange” devices that we imagine or which result from our design techniques but also to train our younger undergraduate students in class or at the doctoral level in the design of satellite components. The CST University Publication Award confirms that we are taking full advantage of the CST tools and it is an incentive for us to continue exploring their possibilities.

What’s next for you – are you working on this technique further? 

We have been working on this idea for years and have applied it to several scenarios. We recently successfully closed an ESA project on its use for future Ka-band multibeam payloads. Although the improvement of a novel concept is endless, we believe that the idea is already very mature and it is being used by TESAT, which is also the current owner of the patent. More generally, we will continue working on microwave filters and passive devices in the future, particularly for space applications. As an example of our current interests, we are currently working hard on a new design method for bandpass filters for the future high-capacity Q/V/W –bands and above (this is a Ph.D. thesis co-funded by ESA). We have already reported very good results in combining excellent frequency behavior, power-handling, and fabrication easiness, the latter using the same milling tolerances employed at the workshop for lower (Ku/Ka) frequency bands.

Is there anything else you would like to mention? 

We thank the CST family for their support. We believe we were one of your first clients in Europe many years ago and you have been a part of many of our research papers ever since. We feel honoured that you have considered our work as an outstanding good practice example for the community.

The team that authored this paper at Universidad Publica de Navarra consisted of Fernando Teberio, Ivan Arregui, Adrian Gomez-Torrent, Israel Arnedo, Magdalena Chudzik, Michael Zedler, Franz-Josef Görtz, Rolf Jost, Txema Lopetegi, and Miguel A. G. Laso.

The research team at Universidad Publica de Navarra. Photo courtesy of Dr. Miguel Laso.

Tuesday, March 6, 2018

Call for contributions: CST SIMULIA EUC 2018

We are in full gear preparing for one of the highlights of the CST year, our annual European User Conference (EUC) and we are looking forward to seeing our users' presentation submissions. There’s nothing quite like the intellectual energy that comes from so many of our customers coming together to share their work, their ideas and to discuss the bright future of simulation.

Customer contributions are crucial to the success of this conference and EUC provides a valuable opportunity to share your knowledge and advance the collective expertise of CST users.
To contribute a presentation, please submit an abstract of between 100-200 words by registering and submitting your abstract online.

For contributors with an accepted presentation who hold a valid CST maintenance contract, the registration fee will be waived. To qualify for this discount, the final abstract must be received by March 15, 2018, and the finished presentation by April 30, 2018. See our website for full details

Still not sure? Hear what people have to say about the EUC experience.

"We have the chance to meet with different companies who are working closely together with electronic products and simulation and I think there is a big benefit for all the people here who attend these sessions, learn new things and learn what is coming in the future." - Damien Kirscher, Altium 

“I think that, being a CST user, this conference puts you in contact with the biggest experts in EM simulation so that you can really take advantage of this during the conference. Also, for those attendees coming from the academic sector, being in contact with people from the industry is always a good opportunity. Likewise, the industry-related attendees can also see the latest advances in design and simulation from some of the most relevant research groups.”
 - Carlos Vicente, Aurorasat 

 "I have attended CST EUC several times and for me, each one is an exciting event. I get to see the software from the user's perspectives. and then develop our own methods and see where we still have empty areas where we should research further. Furthermore, I know many people here who I work very well with and remain in contact with and I'm looking forward to attending again." - Markus Clemens, Bergische Universität Wuppertal

“In my experience EUC is a great opportunity to learn, share and interact with experts in various application areas. It is the ideal place to discuss your ideas and see what other CST users are doing. This event will certainly enrich your simulation experience and hopefully also help you to improve your workflows in the future.” - Theunis Beukman, CST

"The support room is really interesting because I use it to pose my questions. With face-to-face communication it's easier to find solutions." - Tatiana Rijoff, CERN 

We look forward to seeing you in June!

Friday, March 2, 2018

Featured Whitepaper: Efficient Design Layout and Simulation of Integrated Photonic Circuits Using IPKISS and CST STUDIO SUITE

CST and Luceda have been working in partnership since 2016 to make make layout, physical simulation and circuit simulation of optical components easily available within a single framework  Recently, we published a whitepaper that explores photonic circuit simulation using the automated link between IPKISS and CST STUDIO SUITE®. 

Read the full paper here

3D electromagnetic field simulations are a very important aspect of integrated photonics design, describing component behavior when validated models obtained through measurements are unavailable or unreliable. In practice, designers often have to consult a range of sources and people to get their simulation configured properly. As those sources are continuously updated, ensuring that the EM simulations are consistently correct is mostly an organizational challenge. Pressed by tape-out deadlines, design teams often have to manually regenerate their models for every slight change of the component or process. The automated link between IPKISS and CST STUDIO SUITE® gives photonic circuit designers direct access to FDTD or FEM generated circuit models using the validated simulation settings set by device engineers. This ensures that models used by circuit designers can easily be regenerated with validated CST STUDIO SUITE simulation settings. This way, IPKISS keeps models up to date as the component layout, fabrication processes, operating conditions and material models evolve from design to design. In this paper, the IPKISS-CST STUDIO SUITE link is introduced and its use is exemplified in a design of a glucose sensor.

Tuesday, February 20, 2018

2018 Getting Ahead eSeminar series

 Our popular Getting Ahead eSeminar series is back for another year with some very informative tutorial-style eSeminars that focus on practical solutions to common design challenges.
We have upcoming eSeminars on optical simulation (this Thursday, Feb 22!) antenna design, RF breakdown as well as simulating particle sources and lightning strikes. Check out the full roster and register for those that pique your interest. Whether you currently work with one of these applications or you want to learn more about something new, we think you will find all of these eSeminars enlightening!

“These popular eSeminars directly address specific design scenarios that our users frequently face.The tutorial style makes these eSeminars accessible for engineers of all levels
who want to improve their practical understanding of how to use electromagnetic simulation and analysis in the design process.”- Dr. Martin Timm, Director of Global Marketing, CST.

The schedule is as follows:

Getting Ahead with Compact Models 
February 15, 2018- Available on-demand

Discover how to use Compact Models in the Transmission-Line Matrix (TLM) solver to speed up the electromagnetic simulation of models with small features like slots, seams and vents while maintaining the accuracy of the result, a capability particularly useful for EMC simulation.

Getting Ahead with Optical Simulation
February 22, 2018

Discover how CST STUDIO SUITE® can be used in the design process of photonic components.This eSeminar will guide you through the process of simulating photonic components with two examples, demonstrating how to tackle photonic integrated circuits (PIC) and photonic crystals in CST STUDIO SUITE.

Getting Ahead with Antenna Design
March 1, 2018

This eSeminar will feature an online demonstration of   different antenna and array design workflows. We will highlight some of the advanced features and options available in Antenna Magus and CST STUDIO SUITE® and consider the challenges facing antenna designers in modern, evolving industries and applications.

Getting Ahead with RF Breakdown Simulation
March 8, 2018

This eSeminar will review the fundamental aspects of RF breakdown in gases, and demonstrate how to determine the breakdown power level without the need to design the complete microwave filter. In particular, we will discuss the main parameters affecting the discharge breakdown threshold such as frequency, pressure, temperature and dimensions.

Getting Ahead with Particle Sources
March 15, 2018

Don’t miss CST’s new eSeminar demonstrating the electromagnetic simulation of four different particles sources in CST STUDIO SUITE® 2018. Charged particle dymanics expert Dr. Monika Balk will guide you through the simulation of a Pierce-type electron gun, a field emission source, an ion source and a magnetron cathode.

Getting Ahead with Lightning Strike Simulation
March 22, 2018

Simulation plays an important role in evaluating system performance when subjected to Electromagnetic Environmental Effects (E3) and for investigating strategies for protection. In this eSeminar, we will show how EM field simulation can be used to provide insightful information with respect to lightning attachment/zoning analysis as well as transient current and magnetic field immunity of relatively large platforms such as aircraft.

Tuesday, January 23, 2018

CST Filter Design Technology: a Powerful Toolkit for Microwave Engineers

In recent years, CST's filter design and analysis technology have continually improved, resulting in exciting new tools that facilitate design, analysis, and optimization. We spoke to one of CST’s resident filter experts, Dr. Theunis Beukman about the latest solvers and features that make CST STUDIO SUITE® such an excellent tool for designers.

If you want to learn more, our Filter Design Workshop is fast approaching and registration is open! The workshop will take place on February 27th outside Washington D.C. and will no doubt benefit filter designers of all levels and areas of focus. We also recommend checking out our 2017 eSeminar, "Overview of CST Filter Design Technology" you can watch on-demand.

What new features for filter design and tuning has CST recently introduced?
Fields in a multimode cavity filter
simulated in CST STUDIO SUITE® 

Over the past two years, in particular, we introduced many new features for filter design and tuning. A vital contribution in this regard came with CST Filter Designer 3D. This tool provides the capability for synthesizing a coupling matrix based on the user’s input of specifications –including arbitrarily placed transmission zeros for bandpass, bandstop or diplexer filters. CST Filter Designer 3D is much more than just a synthesis tool. It also has a unique feature that allows you to extract the coupling matrix from the S-parameters of your EM simulation model, which provides insight into the operation of this 3D model without having to dissect or analyze it using surrogate circuits. Another great feature is our moving mesh technology that helps overcome “mesh noise,” which is a common simulation issue. Moving mesh enables us to tune up very sensitive filters that can have fractional bandwidths of 1% and below.

How does CST’s new coupling matrix based optimization improve the filter design 

I think any person who has tried to tune up a filter knows the cumbersome workflow and time-consuming routines they have to endure (perhaps with a minimal number of exceptions). What we’ve done is taken the new capabilities of CST Filter Designer 3D and implemented an optimizer dedicated for coupled-resonator filters. Our software eliminates that time-consuming effort when tuning and provides an efficient solution that is far more capable than brute-force optimization.

Besides EM, what multiphysics effects do filter designers also need to watch out for?

When it comes to transmitter systems, front-end filters typically need to be able to handle high input power. This can lead to various unwanted effects that require advanced simulation during the design phase. A very capable tool in our arsenal is SPARK3D, which uses advanced algorithms to calculate possible RF breakdown either in a vacuum or in gas – perhaps better known as multipaction and corona discharge. Another potentially harmful effect is heating due to power dissipation in a device or adjacent components. This can lead to substantial detuning of the filter structure and therefore requires both thermal and mechanical simulation which are available in CST STUDIO SUITE® 2018. At the workshop, we will have two dedicated sessions for these topics.

Speaking of the workshop, could you give us an overview of what will be covered? Who should be sure to attend and why?

This workshop is a fantastic resource for all filter designers, regardless of whether you are currently using CST STUDIO SUITE® or you’re just curious about the topic of filter simulation. This workshop will provide you with a solid overview of the complete set of simulation solutions that can be applied in practical filter design.

The program will include topics like synthesis, the realization of distributed models, tuning based on the coupling matrix and multiphysics analyses. There will be a focus on bandpass filter design, though we will also touch on other types such as lowpass/highpass and multiplexer filters. We will showcase the different tools that are applicable in each stage of the design workflow and highlight the underlying technologies that make it possible.

Register here for the CST Filter Design Workshop.

Dr. Theunis Beukman is an application engineer at CST - Computer Simulation Technology in Darmstadt, Germany. He received his MScEng (cum laude) and Ph.D. degrees in Electrical and Electronic Engineering from the University of Stellenbosch, South Africa, in 2011 and 2015 respectively. During his Masters, Dr. Beukman worked on tunable wideband filters for the Square Kilometre Array (SKA) project and spent several months as a visiting researcher with the filter group at Heriot-Watt University.

Friday, January 19, 2018

Top 5 Webinars of 2017

Webinars are one of our most popular content mediums, every year CST presents two webinar series' and many individual webinars on hot topics from across the industries that we serve. We crunched the numbers, and these webinars were the most watched this year. They represent some of the most innovative new technologies from CubeSats to wireless charging.

1. Automotive Radar Simulation

This webinar shows how CST STUDIO SUITE can be used to perform and study all of the design stages of automotive radars, starting from the basic element which is the antenna, through its integration inside a radome, to actually placing and calibrating the whole package inside the car, using CST Complete Technology’s versatility and solver diversity.

2. Cubesat Antenna Design

This webinar reviews modern trends of antennas on small satellites. It presents a basic design scenario and how software tools such as Antenna Magus and CST STUDIO SUITE can be used to
address the challenges it presents.

3. Inductive Wireless Charging for Automotive Applications

This webinar focuses on workflows and best practices to predict the performance of individual coils as well as inductively coupled systems in the automotive environment. In particular, the accurate loss prediction in litz wires and ferrite materials is of great importance is discussed in detail. 

4. CST STUDIO SUITE 2018 Technology Highlights

The CST STUDIO SUITE 2018 release contains many new features and improvements for solving Maxwell’s equations and related problems. This webinar highlights some of the best of those improvements and new features, including classical EM-simulations, workflows, multiphysics, coupled simulations, among many others.

5. Antenna Design for a Home Multimedia Device 

This webinar covers the simulation techniques and tools that allow new antenna concepts for Internet of Things devices to be developed and tested quickly at a very early design stage, leading to a better connected device and a reduced overall device design time.

We look forward to another year of great webinars as we at CST explore and explain the latest technological advancements through electromagnetic simulation. Keep an eye out for the "Getting Ahead With..." our tutorial-style webinar series which will be announced soon.

Wednesday, January 10, 2018

Top 5 CST Articles of 2017

Every year, thousands of visitors check out the technical content in CST's large library. With articles and webinars that cover all of the markets and industries that we serve, it's always fascinating to see what was most interesting to our followers.

1. A Dielectric Lens Antenna with Enhanced Aperture Efficiency for Industrial Radar Application 

One application of RADAR (RAdio Detection And Ranging) is to measure the distance to a moving or fixed object using an electromagnetic wave. The distance of the object is determined by the time difference between the transmitted and reflected wave. This article describes such a distance measurement using a RADAR system for measuring the tank filling level in an industrial storage tank.

2. Microstrip Patch Array Design

This article explains the design process for a planar microstrip patch array for WLAN frequencies using the circuit and full-wave 3D solvers and optimization tools in CST STUDIO SUITE®. 

3. Five-Section Microstrip Hairpin-Filter

This practical article covers the step-by-step simulation of a Five-Section Microstrip Hairpin-Filter.

4. Optimization of Torque in a Permanent Magnet Synchronous Motor (PMSM) for Traction Applications

This article summarizes the simulation and optimization of a 200 Hz, 8-Pole Permanent Magnet Synchronous Motor (PMSM) typically used for traction applications in automotive and transportation systems.

5. RFID Reader-Coil, 13.56 MHz

This article details the simulation of a specific  RFID Reader-Coil using CST's frequency domain solver. 

Mesh details of the tetrahedral Mesh used for the Frequency-Domain Solver in CST MWS. 

Tuesday, January 2, 2018

CST Lab: Improving Design with Measurement and Simulation

“Why don’t my simulation results agree with the measurement?” This is the question I sometimes heard from our customers and which inspired us to start CST Lab, which is a project that promotes the combination of simulation and measurement to fix the perennial problem of mismatched results. CST Lab was officially started two years ago, and for the past 5 years we have been working in this space through our joint workshops with Rohde & Schwarz, one of the global leaders in measurement instruments and techniques. These workshops were very well received since the content went well beyond a typical product presentation. The workshops examine critical points in the design process and include hands-on learning for both measurement and simulation portions.
Recently, we introduced a two-day vector network analyzer (VNA) training course, which covers the fundamentals of microwave measurement and the obtained measured data are used during the second day for the material characterization and component modeling.

Providing customers with comprehensive technical support

CST Lab’s objective is to provide our customers with broader, application-based technical support where we deal with the overall design process instead of limiting the support to the simulation portion only.  
CST Lab at European Microwave Week 2017
CST Lab supports our customers who can benefit from our extensive knowledge concerning measurement and its interpretation. The approach is beneficial to all engineers who need to reduce the length of the design cycle making the design process more robust and reliable.  

Benefits of combining simulation and measurement

There are many benefits of combining simulation and measurement during the design stage. Each of the domains is suitable for different tasks. For instance, simulation allows us to do what-if analysis without the expensive and lengthy manufacturing process. We can employ an automatic optimization engine to improve the device parameters. Also, simulation provides an inside view of EM field visualization, which provides a better understanding of the physical mechanisms.
On the other hand, material properties, which are the critical input information for 3D EM simulation, need to be determined using the measurement of a simple, well-defined sample. Measurement is usually very fast, providing the results in real-time. Also, the measurement contains all the physical effects of the device under test (DUT).  So if we combine both domains, we can always be sure we have used the best-suited tool for the particular task.

Common misconceptions

There are a few common misconceptions or mistakes that we encounter and correct when we are working with users or giving workshops on simulation and measurement. The most common mistake is that people simulate something different than what is measured. A typical case is a microwave circuit or antenna that includes an adapter is measured, but because the engineer assumes the adapter behaves ideally, it is not included in the 3D model. However, if we look closer and measure its S-parameters, the results show that the troublemaker is in fact, the adapter. The adapter in this example can be replaced with any other piece of structure that is present in the experiment, but it is missing in the virtual model. Sometimes, a very tiny detail might cause a significant discrepancy, and it can be challenging to reveal this.
If we look at electromagnetic compatibility (EMC), we can find an example of a typical misconception. A standard initial request of a potential customer dealing with an EMC issue is: “Please put all the system including all the nonlinear circuits and mechanical parts into the 3D EM simulator and show us the agreement of emissions to our measurement”. This is a very inefficient approach since it would require a lot of time to transfer all the complexity of the device to the virtual model including, possibly, the effects of the environment where the device being tested was measured. Regardless, this approach won’t help to solve the EMC issue if the aim is just to replicate the measurement with the simulation. Instead, we recommend capturing only the most relevant portion for the principal study and finding the emission sources utilizing field visualization. As soon as we understand the how the emissions are generated, we can take action to suppress them. Typically that can be achieved just by modifying the PCB layout. Then, we may add a bit more complexity in the final step before applying changes to the physical sample to complete the verification loop.

The future of CST Lab

Our efforts with CST Lab are well received, and our customers actively cooperate since they see the benefits of combining measurement and simulation.
During the last three years, we have developed several novel workflows that speed up the design process and which enable our customers to create much more robust virtual models with an accuracy we haven’t seen before. Besides the development of further new approaches, the most critical task and challenge for the future will be the transfer of this knowledge to technical practice.   In fact, CST recently jointly presented a course from the well-respected European School of Antennas titled “Combination of Measurement and Simulation.” This is a wonderful example of companies and academia coming together to promote this approach to design.

Want to learn more? Check out these webinars in our archive and sign up with MyCST to be notified of upcoming training, workshops and other CST Lab related events.

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Dr. Vratislav Sokol
Senior Application Engineer

Vratislav Sokol received his M.Sc. and Ph.D. degrees in radioelectronics from the Czech Technical University in Prague in 2000 and 2004, respectively. He was a post-doctoral research associate with Cork Institute of Technology in Ireland where he dealt with an ultra-wideband transceiver. His activities are focused on microwave circuit design and modeling using electromagnetic field simulators and precise microwave measurement and calibration. He has been with CST since 2006 as an application engineer.