• 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

EM Simulation of a 6.7 GHz Coaxial Bragg Reflector

Bragg reflectors, like other periodic structures, exhibit stopband features. Distributed Bragg reflectors are built upon multiple layers of materials with different refractive indices or perturbation of some geometrical characteristic. In this example a Bragg reflector is implemented in coaxial form. Its stopband behavior occurs at the frequency where the periodicity is about a half-wavelength size. Each layer produces a reflection on the incoming wave, so that after several constructive and destructive interferences a stopband region is formed, where the wave does not go through the structure and it is reflected back to the input port. A model of the Bragg reflector was created and simulated using CST MICROWAVE STUDIO® (CST MWS).

Figure 1: Photo of the actual device with CST MWS model
Figure 1: Photo of the actual device with CST MWS model

The ease of modeling this structure with CST MWS and its fast simulation with the transient solver enabled the test of several different configurations. The optmized structure has 10 disks and is built with stainless steel, as shown in Figure 1. It is devised to be operating together with a high-power 6.7GHz monotron tube, in order to block unwanted reverse side emissions. Therefore, the stopband is designed to be centered around this frequency. The CST MWS model is also shown in Figure 1.

Figure 2: Measurement setup

Figure 2 shows the measurement setup, where a sweep oscillator injects energy into the structure, and on the other end there is a pyramidal horn antenna which collects the signal. The ultimate goal is to measure the S21 between both terminals, as to see whether the energy of that particular frequency range is blocked.

Figure 3: 3D Electric field and Power Flow Plots at various frequencies

Further insight into the effectiveness of the reflecting structure is given by 3D plots provided by CST MWS. As illustrated below by electric-field and power-flow plots, the left panels show that an incident TEM wave at 2.0 GHz, located in the left pass band (Fig. 3), is fully transmitted along the reflector. At 10.0-GHz wave is partially transmitted (right panels), while at a frequency located in the middle of the band gap (Fig. 3) , namely 6.7 GHz , the wave is strongly reflected (center panels).

Figure 4: Comparison between simulation and measurement of S21

The CST MWS Transient Solver was used to perform the simulation. Excellent correlation between measurement and simulation results can be seen in Figure 4. Even the two modes of resonance outside the stopband region, located at 10 and 12GHz, measured by the setup present in Fig.3, were predicted by the simulation.


Barroso J.J., Castro P.J., Neto J.P.L. and Pimentel G.L., " Experimental characterization of a 6.7GHz coaxial Bragg reflector", Review of Scientific Instruments, 78, 2007.

Rate this Article

0 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.