Continue to Site

Welcome to EDAboard.com

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.

connecting two resonators in series

yefj

Advanced Member level 4
Joined
Sep 12, 2019
Messages
1,239
Helped
1
Reputation
2
Reaction score
3
Trophy points
38
Activity points
7,460
Hello , I have built two resonator which are excited and connected with coax lines.
at resonance as you can see below the electric field in much stronger on the line then on the resonators themself.
I know that the coax line acts as a resonator itself, and i get half wavelength pattern.
But why the electric field is much stronger there then on the resonators on the edges?
Thanks.


1713430685851.png
 
It seems that you are not at resonance frequency of your resonators, so the only resonance that you see is the resonance of the line with mismatch on both ends.
 
Hello Volker, How can you reccomend to improve the matching ?
I have the same coax cable running threw them.
 
As I wrote above, I think that your resonators are not tuned to the correct frequency. Look at S21 of the total structure, maybe that shows something.
 
Hello Volker,When i have designed those resonators i saw the desired modes.
And i still see them but compared to the coax line the field of the resonator are very weak.

So i will try and tune the first resonantor and i will see the field stronget then the coax?
maybe because the distance between the inner and outer conductors are so small so the E-field is very strong because V=E*d :)
 
So i will try and tune the first resonantor
Before you start tuning, show us your S21 results for the total structure
--- Updated ---

I wonder if those strips will melt with 746 V/mm. What is the current?
Don't forget that this is simulation only ... The EM tools use some large default value for excitation, such as 1A. It's a linear simulation, so the absolute value can be scaled to your liking.
 
Before you start tuning, show us your S21 results for the total structure
--- Updated ---


Don't forget that this is simulation only ... The EM tools use some large default value for excitation, such as 1A. It's a linear simulation, so the absolute value can be scaled to your liking.
Yes Volker, "will melt" meaning future tense. I would expect the stripline to look more robust to handle this power. Wouldn't you?

I might expect 5mm w. over 2.5mm h. of Kapton or alumina or more.
 
Last edited:
S21 and S11 are shown bellow.
Ok, there are multiple resonances, and it seems that you 14.41 GHZ E field plot shows one of them.
For which resonance frequencies did you design the two resonators? Do you have S11 and S21 results for the individual resonators also?
--- Updated ---

more robust to handle this power.
As I wrote above, this is source power a default simulation setting, not the power used in the real circuit. I guess this resonator will be used in the oscillator that yefi is working on.
 
Hello Volker, the S11 S12 of each resonator is shown apart. I know that i somehow need to look for the resonanceswhich are in teh resonantors themself any intuition how to find them?

Another question is how exactly this structure could be used for ? of connecting two resonators in series?
Thanks.
First resonator S-params:
1713860354787.png

1713860270438.png




Second resonance:

1713860502396.png


1713860536317.png
 
Hello Volker , I assumed that they always will differ .
I thought i could tweak them on the united structure.
 
I thought i could tweak them on the united structure.
Ok, I think tuning is your next step then.

The 14.41 GHz plot that you showed is not the resonance of resonator 1 or resonator 2, that seems to be the resonance of the line with mismatch on both ends.
 

    yefj

    Points: 2
    Helpful Answer Positive Rating

LaTeX Commands Quick-Menu:

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top