CST MICROWAVE STUDIO® (CST MWS) has been succesfully applied to the simulation of wide-band dual-mode horn antennas which exhibit rotationally symmetric beams and low side-lobe levels. This is acheived by placing a dieletric ring inside the antenna. The size of the antenna corresponds to approx. 10 * 6 * 6 lambda rendering this an excellent application for the CST MWS Transient Solver.
This model was created and measured by Rafael Ltd., Haifa, Israel. We would like to express our gratitude to Rafael for permission to publish these results.
Figure 1 shows the structure of the antenna. The inner Teflon ring was modelled with an epsilon of 2.08 and quarter symmetry was applied. Any arbitrary number of farfield monitors can be set with nearly no effect on the simulation time. Monitor Frequencies of 10.7, 11.65, 12.6, 13.55 and 14.5 GHz were defined for this simulation....
The structure was created in CST MWS using the Loft feature to create the taper between the feed and the mouth of the horn. The Shell Object feature was used to hollow out the horn to a desired thickness with openings at both ends.
As the farfield plots demonstrate, excellent results were obtained with CST MWS . The simulation time was just 1 Hour and 14 minutes on an AMD XP 1500+, 1GB RAM System.
The principle of this Potter-Horn is described in the paper:
Dielectric-loaded horn antenna Satoh, T.; Antennas and Propagation, IEEE Transactions on, Volume: 20 , Issue: 2 , Mar 1972 Pages:199 - 201