• 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

Simulation of a Dual-Band Antenna for a Sounding Rocket

Sounding rockets are relatively small rockets developed primarily for high-altitude experiments, and are used in many academic and low-cost research missions. Antennas for sounding rockets need to be compact, lightweight, omnidirectional and have a form factor that allows them to be integrated on the rocket without causing drag, which can make their design challenging. A group at ENSEIRB-MATMECA, Bordeaux Institute of Technology, used CST STUDIO SUITE to develop a low cost antenna that can be integrated into the nose cone of a rocket and transmit payload and telemetry data in the 869.4–869.65 MHz and 2.4–2.4835 GHz frequency bands.

In the course of flight, the maximum distance between the rocket and the ground base station is 2.5 km, and the elevation relative to the base station varies between 90° and 160° (Figure 1). However, to minimise the risk from malfunctions such as parachute failures, the antenna was designed to have maximal elevation coverage. Full specifications can be found in [1] – the most critical is that in the upper band, the maximum allowed gain variation is 8.7 dB....

Figure 1: A diagram of the rocket’s flight. Over the course of the flight, the angle between the rocket and base station varies considerably.

To avoid having any part of the antenna protrude out of the rocket and cause drag, the entire thing is integrated inside the fiber-epoxy nose cone. Although a broadband monopole would be one possible solution, it has few degrees of freedom and this makes it difficult to minimize coupling to the rocket fuselage. A bicone antenna has more degrees of freedom, and can be constructed in a cross-pattern that achieves a low weight but omnidirectional performance (Figure 2).

Figure 2: The antenna design. Full dimensions are available in [1].

In order to find a design that meets the specifications, the group optimized the antenna parameters using the time domain solver in CST STUDIO SUITE®. Sweeping the parameter g  (the gap between the upper and lower halves) allowed the group to impedance match the antenna in both bands (Figure 3 and 4), chosing g = 1mm as the optimum.

Figure 3: (a) Real and (b) imaginary part of antenna impedance Z11 versus g.

Figure 4: Antenna |S11| versus g.

In designing the length of the taper (L11), there needs to be a compromise between two competing effects. Simulation revealed that increasing L11 reduces the coupling between the antenna and surface waves on the rocket body at 2.45 GHz, and therefore improves the coverage of the antenna. However, this also has the effect of reducing the gain of the antenna. A parameter sweep of L11 from 20 mm to 50 mm found that the best compromise was found at L11 = 40 mm, where the 8.7 dB gain variation range at 2.45 GHz is ? = 18° to 177° (Figure 5).

Figure 5: Simulated elevation radiation patterns, for ?=0°, for varying L11 on a 1.8-m-long fuselage at (left) 869.5 MHz and (right) 2.45 GHz.

A prototype was constructed (Figure 6), and good agreement was found between the measured and simulated results (Figure 7) – simulation also allowed the performance of the antenna to be analysed as installed on the full-size rocket, which would not fit in the measurement chamber. The antenna met the requirements and was integrated into the Project Artemis rocket, which subsequently won the 2015 Prix Espace et Industrie (Space and Industry Prize) from the French government space agency CNES.

Figure 6: The antenna under test, on a section of rocket fuselage. Students would like to thank the Poly-Grames research center, Montréal, Canada, for the measurement.

Figure 7: Radiation patterns at (a) 869.5 MHz and (b) 2.45 GHz at ?=0 – measured and simulated on a 0.28 m section of fuselage, and simulated on the full 1.8 m fuselage.


[1] J. Prades, A. Ghiotto, E. Kerhervé and K. Wu, "Broadband Sounding Rocket Antenna for Dual-Band Telemetric and Payload Data Transmission," in IEEE Antennas and Wireless Propagation Letters, vol. 15, pp. 540-543, 2016. doi: 10.1109/LAWP.2015.2457338

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.