Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
Just give it a shot, reduce your spacing a little. You'll (or you should) see those sidelobes moving outwards. For a while, I don't think coupling will be strong. If you find out that the coupling is strong, I advise you to change your feeding scheme.
For this case tapering will not help you...
In an antenna array, the overall pattern is the multiplication of the element pattern and array factor. Even if your single patch element does not have any sidelobes (which may be the case if it's a conventional patch) your array factor WILL have sidelobes if center to center spacing between...
It is not easy to give any rule of thumb on lower bound as it is related to coupling coefficient. However, for the maximum, I can tell the coupling becomes very small for spacings greater than overall height (i.e. the distance between two outer shields) of the striplines.
There are standard waveguide sizes coded with WR prefixes (for instance WR90 for xband, i.e. 8.2-12.4GHz). I don't know if you already have a fixed waveguide dimension. If not, you can go with WR340 (it is given as 2.2GHz to 3.3GHz (for single mode operation), but is has a margin on the low end...
I think your main problem is not the symmetry but the patterns having high sidelobes. Your sidelobes are most likely due to array factor. You should try a small spacing between your elements, say lambda/2 or slightly smaller.
They have effects on impedance matching, but they are not crucial. Just sticking the inner conductor of the coax into the rectangular waveguide can still provide you less than -10dB S11. According to my experiences the center pin should go slightly more than half the height of the rectangular...
It's not an error. It's a warning. It means that there are some modes supported by your port which are above their cut-off frequencies. For this kind of simulation I don't see that being a problem, but you may try to increase the number of modes included (at the waveport menu) to see (and make...
I do. I haven't done reflectarrays but I have developed a finite element rigorous coupled wave method for periodic structures. In fact I'm doing a sort of polarization selective surface design.
I checked couple papers (I cannot check all of them, just on ieee, there are about 165 journals) but I...
You don't have to simulate it. The results are obvious. The case with "only front ground plane", and "two ground planes" will be same. If you simulate "only second ground plane" to subtract it's effect on your reflection you will get wrong results, because in two ground plane case, your second...
Ok, so you have your results matched to paper.
Now the question is "why aren't we subtracting the ground plane?" (the paper didn't subtract it either)
The other paper/papers may have subtracted it to show some certain effect they wanted to describe, or to show how this structure is different...
Why do you need to do this? To me, actually, subtraction needs justification, instead of trying to justify not subracting. If you want to see the effect without ground plane, you already have it. This way you take the direct ground plane reflection out, but leave the coupling terms in there...
So ground plane results don't match for both ground plane separations? It can be because of the reference plane setup or something else.
0.1 lambda ground plane distance is tricky. What is your mesh size? Make sure your ground plane and structure are not on the same cube (i.e on different sides...
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
