Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Problem with S11 parameter

Please login with a confirmed email address before reporting spam

I created in Comsol a resonator cavity with a feed (in the picture) that works at GPS frequency (1.57 GHz). When I try to extract S parameters I don't understand the behavior because the values are very high (as you can see in picture). Can somebody help me?


2 Replies Last Post Oct 9, 2016, 3:36 p.m. EDT

Please login with a confirmed email address before reporting spam

Posted: 8 years ago Oct 9, 2016, 2:25 p.m. EDT
I agree that number looks weird. What do the fields look like inside the cavity? What are your materials? Is there lossy material anywhere? How did you decide what frequency to the cavity resonates at, did you do a sweep?
I agree that number looks weird. What do the fields look like inside the cavity? What are your materials? Is there lossy material anywhere? How did you decide what frequency to the cavity resonates at, did you do a sweep?

Please login with a confirmed email address before reporting spam

Posted: 8 years ago Oct 9, 2016, 3:36 p.m. EDT

I agree that number looks weird. What do the fields look like inside the cavity? What are your materials? Is there lossy material anywhere? How did you decide what frequency to the cavity resonates at, did you do a sweep?


Cavity size has been designed by considering fondamental TE mode. I've used a coaxial cable as feed with a little extension of inner conductor to couple energy inside the cavity. I've simulated a frequency range between 1.45[GHz] and 1.65[GHz]. However, you can see the field in the picture below.
Cavity has air inside and PEC as boundary.
[QUOTE] I agree that number looks weird. What do the fields look like inside the cavity? What are your materials? Is there lossy material anywhere? How did you decide what frequency to the cavity resonates at, did you do a sweep? [/QUOTE] Cavity size has been designed by considering fondamental TE mode. I've used a coaxial cable as feed with a little extension of inner conductor to couple energy inside the cavity. I've simulated a frequency range between 1.45[GHz] and 1.65[GHz]. However, you can see the field in the picture below. Cavity has air inside and PEC as boundary.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.