# Recent content by mmrobles

1. ### Chip Antenna simulation for CST Microwave Studio

Hi, anyone here knows any tutorial or has tried simulating chip antenna in CST? I am trying to model one but I am not sure if I am doing it properly without reference. How do you model the dielectric in the chip? And do you need to simulate the matching network as well? Any help would be...
2. ### How to split S-parameters into two symmetric halves? For de-embedding.

Thanks a lot for this. I'm trying to look for it at Google for days and I can't find the right keyword. So it's called "S-parameter bisection". I'm not an ADS user, but I'm trying to read the literature. I thought it was just a straightforward mathematical calculation, but seems like it is not...
3. ### How to split S-parameters into two symmetric halves? For de-embedding.

Thanks for the reply. I got a problem with the #4 though. So if I have a connected symmetric DUT such that Sleft = [S11 S12; S21 S22] and Sright = [S22 S21; S12 S11], does converting Sleft->Tleft=[T11 T12;T21 T22] make the Tright=[T22 T21; T12 T11]?? It's the S-parameters of my left and right...
4. ### How to split S-parameters into two symmetric halves? For de-embedding.

I'm trying to characterize a WR90 waveguide-to-coaxial adapter thru the VNA by attaching it to an identical pair. So the coaxial ends of each adapter are connected to the VNA ports while the rectangular ends are connected against each other. Now I measured the full S-parameters for these...
5. ### Mode matching technique for step transition in Rectangular to Circular Waveguide?

Thanks for your reply zhul3. I was thinking for that same formula as my reference as well, but not really sure for the exact mathematical expression for two-steps and above. So I'm asking for some references, coz I can't find any equation relating Zt and the height and width, aside from here...
6. ### Mode matching technique for step transition in Rectangular to Circular Waveguide?

I've been designing step transitions for Rectangular to Circular waveguide, and I'm trying to search for any concepts regarding how to determine the optimal dimensions of the intermediate steps for this transition. From what I learned each step length should be kept at least to 1/4 of the guide...

8. ### how to design a taper from rectangular waveguide to circular waveguide using HFSS

Thanks a lot for your reply! I actually searched the forum for circular waveguide designs and have found lots of related questions about this, but only few responses. Fortunately I found some useful replies, and I think I've managed to make my simulation work now both for HFSS and CST. It is...
9. ### How to properly define Circular TE11 waveguide mode in CST and HFSS?

I'm designing a rectangular to circular taper transition in HFSS and CST, but doesn't seem to get it right. How should I define the TE10 for rectangular and the TE11 for circular (they say this is degenerate but i dont undestand what that means) in CST? or HFSS? Can someone explain this to me...
10. ### how to design a taper from rectangular waveguide to circular waveguide using HFSS

Hello Hash! This might be an old post, but I'm currently doing this same procedure at the moment. But I'm have no idea in defining the ports correctly for the TE10 of Rectangular and TE11 of Circular. I just used the Integration Lines from the tutorial, but don't know about the circular port...
11. ### Improving Waveguide-to-Coax Transitions

Oh... Thanks for your second input. That was helpful. I already did study a simple wgcx transition (thru simulation) for a project, and now looking forward on how to extend my research further. As I couldn't see related literatures on how these transitions are improved beyond the empirical...
12. ### Improving Waveguide-to-Coax Transitions

I have a question.. How does a ridge or double ridge transition differ from a regular waveguide to coax transition? What does the ridge do to the output?
13. ### Improving Waveguide-to-Coax Transitions

Do you have some links/sources of these steps from Agilent? :) Share me sources if you find any. Thanks.
14. ### Improving Waveguide-to-Coax Transitions

I've seen some researches on waveguide-to-coax transitions doing simulations to improve the response of the transitive by varying the design parameters/dimensions of the transition until it gets the best match possible. Now beyond than that, does anyone know other methods on how a wg2cx...
15. ### How to deembed the effects of the waveguide on a waveguide-to-coax transition?

Oh, I see. Well, actually my waveguide-to-coax transition uses an Aluminum material (which is a lossy metal) as its shell, that's why my professor told me to de-embed the waveguide from the transition, but did not told me how. Now CST only provides a de-embed function only for the phase value...