• Which Products are you interested in ?

    CST offers a wide range of EM simulation software to address design challenges across the electromagnetic spectrum, from static and low frequency to microwave and RF, for a range of applications, including EDA & electronics, EMC & EMI and charged particle dynamics.

  • Antenna Magus
  • IdEM
  • FEST3D
  • Optenni Lab
  • Looking for a Training, Workshop or eSeminar ?

    CST STUDIO SUITE® is being demonstrated at trade shows and workshops all over the world. Take a look at the list of conferences and exhibitions CST will be attending and get further information regarding CST workshops, eSeminars and training days.

  • TrainingsRegular training courses are held in CST's offices in Asia, Europe, and North America. Please check our trainings section for detail of trainings in all over the globe. Advance registration is normally required.

  • WorkshopsCST hosts workshops in multiple languages and in countries around the world. Workshops provide an opportunity to learn about specific applications and refresh your skills with experienced CST support staff. Make sure you visit our workshop section.

  • eSeminarsThroughout the year, CST simulation experts present eSeminars on the applications, features and usage of our software. You can also view past eSeminars by searching our archive and filtering for the markets or industries that interest you most.

  • Check our latest Events
  • Why create a MyCST Account ?

    A MyCST account may facilitate your access to many of the offerings on the CST website, for example the registration for eSeminars and the watching of eSeminars recordings, setting email preferences, and there is more functionality to come. It is required to participate in workshops and trainings.

  • Personal PreferencesAllows you to update your email preferences and areas of interest. It helps us to personalize your experience.

  • EventsSearch for events by location, industry and application. Once you are registered, you will be able to manage your registrations and check important details about your events. This section also provides you with a repository for Workshop & Training material.

  • LibraryYou can collect articles you find on the CST website to reference or read later by clicking on the “Add this article” button at the bottom of the article page.

  • Create Your Own Account
  • Need technical Support ?

    Customers can customize their accounts once they have completed the account creation process. This platform acts as vivid interface between CST and our customers.

    We therefore offer access to the latest Service Packs (including an automatic notification that a new Service Pack is available), a steadily growing database of Frequently Asked Questions (FAQs), Application Notes and Training Videos, as well as an individual FTP section for easy exchange of large files with our support team.

  • Do I need an Account?To access the Support Site a valid maintenance contract and a one-time registration is required.

    Please note that your Support login does not work for the MyCST account.

  • Get Support
  • How to request a Trial License ?

    Get your license in only three steps:

    1. Fill in the required fields in the contact form on the right and click "Send Us Your Request".

    2. Lean back and wait until one of our CST Experts contacts you.

    3. Enjoy a our trial license.

  • Student Edition

    Student Edition The CST STUDIO SUITE® Student Edition has been developed with the aim of introducing you to the world of electromagnetic simulation, making Maxwell’s equations easier to understand than ever. With this edition you have, bar some restrictions, access to our powerful visualization engine and some of the most advanced solvers of CST STUDIO SUITE.

    Student Edition

CST – Computer Simulation Technology

3D EM Simulation in the design flow of high speed multi pin connectors

Application and Simulation courtesy of Thomas Gneiting, AdMOS GmbH, Frickenhausen, Germany.

This article describes the design flow for a high speed connector using different simulation tools. The goal is to enable a first pass design without time-intensive and costly iteration steps. In addition to other simulation tools, CST MICROWAVE STUDIO® (CST MWS) is used during different stages of the design process to find fundamental design parameters and to predict the behavior of a complete telecommunication system.

The requirement of a new high speed multi pin connector is to enable a data transmission rate of at least 10Gbit/s in a communication system, (Figure 1), where two daughtercards are connected via a backplane. The connections should be point-to-point connections applying differential signal trace layout. Other technical requirements include: ...

  • 100 Ohm differential impedance
  • SMT interface to printed circuit board
  • Extreme shielding to achieve a minimum of crosstalk between differential signal pairs
  • Minimum signal skew between the two contacts of a differential signal pair
  • Economical and easy trace routing

Figure 1: Backplane and daughtercard system

EM simulation can be used in the early stages of the design process to help determine the main dimensions of the connector and how it will behave in the aforementioned system. The prototyping process is shown in Figure 2.

Figure 2: Design and prototype process flow

Once the requirements have been defined, a study is performed to establish the conductor dimensions. The main parameters are the trace width and the distance between the differential signal pair of the connector in addition to the distance between the 2 signal pairs inside the wafers. In the design process it is necessary to obtain a realistic prediction of the overall communication system performance. The S-parameters of the parametric connector model were exported in touchstone format and used in a circuit simulator (Agilent ADS) for further analysis. An accurate analysis must include the behaviour of not just the connector but also the connector to PCB board interface, the backplane, daughtercards and signal path vias. This approach allows the performance of the complete communication system and not just the connector to be established. The CST MWS model is shown in Figure 3. It consists of 3 wafers with 4 signal pairs per wafer. It was used to verify the impedance matching, reflection, crosstalk & multiline crosstalk, to generate a SPICE model and to determine the overall system behaviour based on the obtained S-parameters.

Figure 3: CST MWS 3D model of the prototype connector

An accurate 3D simulation using CST MWS is vital for the highly critical and expensive manufacturing process of the cutting tools and plastic housing components. In addition to the investment costs, a major issue is the time at which the first sample is obtained since time-consuming changes to the production tools may be necessary if the sample does not meet the required specifications. The overall time to market is an important factor that is heavily influenced by the design, prototype and test phases. The stamping and molding tools are designed and manufactured to allow a high volume production of the connector system. The investment costs for those tools are in the range of 1€ Million for one type of the connector meaning that the prototyping stage is the most expensive part of the design process.

Figure 4: CST MWS Model of the PCB-connector interface

A reliable CST MWS simlation is therefore vital for obtaining accurate results during this process. The connector to PCB interface, shown in Figure 4, is one of the most limiting factors in speed performance. Parametric studies have been performed to optimize this interface with respect to the reflection and crosstalk behaviour.

Figure 5: Test setup and measurement results

A test vehicle (PCB) was designed to verify the simulated connector behaviour with measurements using a Time Domain Reflectometer and a Vector Network Analyzer. This testboard, shown in Figure 5, contains special De-embedding structures. The simulated results show excellent correlation with the measurement results proving the effectiveness of the simulation process, and moreover, the accuracy of the 3D simulations.

Figure 6: Eye diagram comparison between simulation and measurement

Figure 6 shows a comparison of the eye diagrams between a complete system simulation including the connector and test boards and the appropriate measurements done on the real system. The upper diagram shows the measured eye diagrams while the lower one shows the simulated ones. A data stream signal with 10Gbit/s of a NRZ 8B10B code was applied to both the real and the simulated systems. Good agreement between the simulated and measured results can be seen.

This article has shown the complete design flow of a complex electromechanical device including first rough estimations and ending in complete system simulations. This project demonstrates how the usage of modern simulation tools could lead to a dramatic decrease of design time. The overall costs could be reduced by a one-pass design cycle. All molding and stamping tools for manufacturing of the connector could be produced without a major rework. System designers could use SPICE / Touchstone models of the ERmet zeroXT connector for their feasibilty studies before the first samples are available.

Rate this Article

1 of 5 Stars
5 Stars
4 Stars
3 Stars
2 Stars
1 Stars
contact support

Your session has expired. Redirecting you to the login page...

We use cookie to operate this website, improve its usability, personalize your experience, and track visits. By continuing to use this site, you are consenting to use of cookies. You have the possibility to manage the parameters and choose whether to accept certain cookies while on the site. For more information, please read our updated privacy policy

Cookie Management

When you browse our website, cookies are enabled by default and data may be read or stored locally on your device. You can set your preferences below:

Functional cookies

These cookies enable additional functionality like saving preferences, allowing social interactions and analyzing usage for site optimization.

Advertising cookies

These cookies enable us and third parties to serve ads that are relevant to your interests.