• 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

Coaxial / Rectangular Converter for the High-Power Microwave Applications

This converter is designed to make a smooth transition from the coaxial structure to two rectangular waveguides, each feeding a cone antenna. Figure 1 shows the geometrical structure of the converter as well as electrical fields of the propagating modes in each section, as seen in CST MICROWAVE STUDIO® (CST MWS).



Figure 1: A. Transverse view, B. Fundamental modes in different sections as seen in CST Microwave Studio

Modal analysis performed in CST MWS showed that 13 modes could propagate in the structure. In order to simulate S-parameters three waveguide ports were defined: one in the input of coaxial cable, exciting the main TEM-mode, and other ports at the outputs of the rectangular waveguides. The reflection coefficient of the total reflected power at port 1 divided by input power, as well as the transmission coefficient of Ports 2 and 3 separately at the frequency band of 2-6 GHz are plotted in Figure 2....



Figure 2: (1) Blue: reflected coefficient at Port1 (2) Green: transmission coefficient at Port2 (3) Red: transmission coefficient at Port3

The wavy behaviour of the S-parameters of Figure 2 is due to the presence of higher-order modes, which were excited in the junction between coaxial and rectangular waveguides. As can be seen from the transmission coefficient, in the frequency range 2-6 GHz, more than 80 % power was transmitted to the output ports.

In addition, maximum voltage was simulated with the input power of 200 MW. The maximum value of the electric field at all frequencies did not exceed 95 kV/cm. This is acceptable as the stainless steel used as a material cannot support more than 150 kV/cm.

The preliminary measurements with small input power were done using the test setup shown in Figure 3, where the both outputs were connected to the matched load. Low level power generator was connected to the coaxial input using conical shape.



Figure 3: Measurement setup

The reflection coefficient was simulated in CST MWS taking account the conical shape. Now, the waveguide port was placed at the input of conical shape exciting mode TEM. The simulated reflection coefficient is plotted in Figure 4.



Figure 4: Reflection coefficient simulated in CST MWS

The reflection coefficient was measured using the test setup of Figure 3, and the measured results are seen in Figure 5.



Figure 5: Measured reflection coefficient

As seen from the Figures 4 and 5, the measured and simulated results are very similar. In both plots strong disturbances appear in the frequency range 2-4 GHz, which are probably due to the coupling between higher modes and TEM-mode.

In the future the breakdown experiments are planned to make a comparison between simulated and measured results at high power level.

Refences

Mathian M., Jouvie F., Lecointe D., Bolomey J.-Ch., "Etude d'un convertisseur guide coaxial/bi-guides rectangulaires pour application micro-ondes de fortes puissances (MFP)", CEM 2006, St. Maolo.

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.