• 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.

  • CST STUDIO SUITE
  • CST EMC STUDIO
  • CST BOARDCHECK
  • 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

Direct Transient Co-Simulation of a Step Recovery Diode (SRD) Pulse Generator

The unique network co-simulation feature in CST STUDIO SUITE® enables a direct transient simulation of a 3D structure in CST MICROWAVE STUDIO® (CST MWS) with non-linear lumped components or circuit networks in CST DESIGN STUDIO™ (CST DS). This article shows the application of this feature to the simulation of a Step Recovery Diode (SRD) pulse generator.

The interface between the 3D EM field simulator and the circuit simulator is facilitated by the use of discrete ports. This approach is suitable for the analysis of sub-nanosecond pulse generators, frequency multipliers with high multiplication factor, etc. An arbitrary waveform of the excitation signal can be used.



Figure 1: CST DS Schematic with co-simulated CST MWS model

The pulse generator, shown in figure 1, consists of coplanar waveguide (CPWG) layout including a helical coil, two lumped capacitors and a step-recovery diode (SRD). A spice model of the step-recovery diode SMMD840 is used which also includes the parasitic elements of the SMD package. The pulse generator is excited with a harmonic signal at 60 MHz passing through low-pass filter (capacitor 68 pF and helical coil) reaching a SRD connected in parallel. A strong non-linearity of the SRD produces a very sharp peak, which is additionally filtered by DC blocking capacitor at the output (1.5 pF)....



Figure 2: Voltage and Current versus Time waveforms

The circuit co-simulation is activated by the “MWS Co-simulation” button in the transient simulation task menu in CST DS, while the total simulation time is given by “Tmax” parameter. The input and output signals are recorded using probe P1 and probe P2 respectively. It is necessary to define differential ports of the CST MICROWAVE STUDIO block in the CST DS schematic for correct handling of differentially connected discrete ports 3,4 and 5 in 3D model.

Figure 2 shows the waveforms of the input voltage and current as well as the output voltage. The ratio of the duration of the input signal (60 MHz) to the monopulse output can be clearly seen. The width of the monopulse, 0.45 ns, can be read from the probe results. The sub-nanosecond pulse is produced by the SRD when the current direction changes from forward to reverse. The step-recovery effect occurs close to the maximum derivative of the current (at about 16 ns).



Figure 3: Power spectrum density

The Power Spectrum Density (PSD) of the output voltage signal can be obtained using “1D Template Based Postprocessing“ (1D Result from 1D result/PSD). It can be seen that the maximum of the PSD figure is approximately at 1500 MHz resulting in the multiplication factor of 25 (1500 MHz / 60 MHz).

The application of the network co-simulation feature has been demonstrated on an SRD pulse generator. This feature is unique in that it allows a full 3D structure to be correctly co-simulated with a non-linear circuit network.

Rate this Article

0 of 5 Stars
5 Stars
0%
4 Stars
0%
3 Stars
0%
2 Stars
0%
1 Stars
0%
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.