Display MoreHello Mike,
I am sending dimension of collar ring. Its thickness is 1mm or so. See attachment. I am adding some feeding tips from another book. Please, private use ! Disclosure, reproduction, copying, distribution, or other dissemination or use of this pages is strictly prohibited. TNX
GL & 73
Rasto
I got around to trying this and it seems good in the student edition too. That's all subject to the errors of a coarse mesh. The ring moved the resonance down a little and the VSWR is better, 1.2:1 and the axial ratio much better if the patch is size is scaled down from 65.5 to 65 mm but I am sure there are optimisations here. Axial ratio of 3dB is OK but not great. I tried 64.5 mm - the axial ratio is excellent, 1 dB, but the VSWR rises to 1.3:1. All of this was with the feedpoint at 29mm radius and 16 degrees, repeating with 18 degrees (the published design) gave a better VSWR and axial ratio but a narrower bandwidth.
One thing we never included in the publication was the radiation pattern! There are some examples below for the curious.
I will see if I can optimise, but we are going to need Rasto's help to verify the real performance according to the full CST.