Dielectric Resonator coupled to TWO microstrips

[gecky]

card trans-tech resonator

Hi

I need to model the circuit of a dielectric resonator coupled to 2 microstrips (used in parallel feedback).

I know that the equilvalent circuit is a RLC coupled to either microstrip by transformers. However, texts and technical papers I found seem to avoid explaining the resultant impedence looking towards the DR from the microstrip ends for such configuration.

At best, the transformed RLC values for the DR coupled to 1 microstrip may be found using software provided by manufacturers (eg Trans-Tech's CARD program). Coupling coefficient is given but that is onli good for coupling with 1 microstrip.

Thanks in advance!

 

[mild-seven]

The ADS2003 has the model built inside, I remember.
Try that .

 

[gecky]

Hi

thanks for the reply. I looked... the model given in ADS2003c is that of a DR coupled to 1 microstrip

I need a relation between coupling factor and turn ratio of the transformers so that i may enter the required model as such:
1<--transformer-->RLC<--transformer-->2

The ends 1 & 2 are the microstrips.

 

[DJ]

Hi,
Use and ideal transformer for each side of the RLC equivalent circuit. Bu playing with the K coupling factor you can tune the coupling coeficient.
If you use ADS I can send you the circuit.

D.J

 

[randyding]

you can use hfss to simulate it

 

[gecky]

Thanks guys!

danelad:

Use and ideal transformer for each side of the RLC equivalent circuit. By playing with the K coupling factor you can tune the coupling coeficient.

Just to reiterate, am I right in saying that all I have to do is adjust the turn ratio,T, of the ideal transformer to obtain the coupling coef,k, i need?

In that case is the relationship: k=T^2*R/Zo . R being the resistance of the equilvalent circuit and Zo the characteristic impedence.

By plugging values obtained from transTech's CARD software, I always get T=2^(-0.5) regardless of what k is. This seem to mean that R is already the transformed resistance...

This is quite lenghty, hope you can understand my situation
Maybe you could also mail me the ADS file at lostgecky@yahoo.com so I can see what you mean.

Thanks!

 

[gecky]

Anyone else can help?