Dear Lupin,
As a matter of fact, I am also a newcomer on this type of antenna and cannot give practical answers to your questions.
Actually I spent 10 minutes with google to see how much info if any can be found on it on the web and collected the most useful-looking pages. These pages seem really helpful for a person good at normal antenna theory.
I have built and tuned in practice normal dipoles, ground planes, yagis and rhombic antennas as part of my amateur radio hobby. Satellite reception is not really of interest for me, though am familiar with that topic.
What I can suggest is trying to put your questions to Steve Blackmore for instance whose e-mail is included at the bottom part of the pilotltd.net page, or he may advise someone else. I do not know him.
Also, there is an authority on this antenna (among some others), see
**broken link removed** you could write to him too. His e-mail is on his page. His book, Reflections 2, includes a very good text on this antenna, see his Chapter 22 on the same page. It is downloadable!
My opinion is that this type of antenna is a very well-thought-out type for satellite communication and as such its polarization performance must be excellent. Regarding its usage in array configuration : it should not differ from the general rules valid for normal arrays, this could be figured out by modeling in antenna software.
The difficulty in modeling, however, comes from the curved shapes, though it has been done in HFSS for a single quadrifilar, see paper by Mike Gilbert at
**broken link removed**
There must be other softwares suitable for modeling this type of antenna, I have no further info on them.
Maybe the aboves are of some help, I hope.
unkarc