When any of the “conic” reflectors are used, it is of interest to specify an “ideal” polarization of the incident field such that the currents induced in the reflector flow in parallel paths. This specification will permit the reflector to be formed by parallel conducting wires or slats .
So, I wrote a simple script to plot the induced currents on the reflector (which is a simple paraboloid of revolution). The ideal feed for this particular reflector is Huygens source (see  for further theory). As you can see, the currents flow in parallel paths as expected. But, due to the inherent antisymmetry nature of the feed, the magnitude of the induced current also is asymmetric. I don’t know exactly how this will effect the secondary radiation pattern. But, I thought it is interesting and noteworthy to post !
Irwin Koffman, “Feed polarization for parallel currents in reflectors generated by conic sections”, IEEE Transactions on Antennas and Propagation, 1966, 14, 37-40
For a few more thoughts related to the Ludwig’s cross polarization definitions, click the link below:
My Thoughts on Ludwig Polarization Definitions – II (Last revision: 22/07/2011) … These two articles are meant to understand the concept of polarization more clearly. In my opinion, Ludwig-3 definition is still a good compromise among various available polarization definitions.
Regarding my previous project (MATLAB version of the “Arraytool”, which is not open source)
When I was an undergraduate, I had this wonderful opportunity to study a book by “E. C. Jordan & K. G. Balmain”. The book was Electromagnetic Waves And Radiating Systems. It introduced me to a wonderful world of radiation, fields, antennas and so many other things. But one thing that really attracted me was the concept of analysis and synthesis of antenna arrays. Though the theory provided on antenna arrays in that book is not of advanced level, it gave me an insight into this beautiful world of imaginary electromagnetic waves trying to co-ordinate (interfere) with each other so that they can fulfill their assigned jobs (like scanning or adjusting side lobes, etc).
But unfortunately to analyze even a very simple array, I had to do cumbersome array factor evaluations to finding pattern nulls, gain, etc. I am not saying that those calculations were useless. As a matter of fact, those manual computations give us very interesting insight into concepts such as grating lobes, side-lobe level, etc. However, human brains have their limitations. So, as the number of array elements increases, we need to use computer for all those numerical calculations.
However, we don’t have proper tools to educate students (or engineers) on this topic. Yes, we do have CAD tools such as HFSS, CST, ADS, etc … and they are very helpful for a microwave engineer. But, a devoted tool providing all possible solutions for antenna arrays is not available at this moment.
So, I decided to create a GUI program based on MATLAB which can answer at least some of the very important issues related my favorite topic. This project is still under construction like all my other projects … 🙂
At the time of writing this post, I was not aware of the following tools which also deal with phased array antenna design: