Help me build a coupler with striplines

[qiang]

help me on coupler

i am doing a coupler(800--200MH),with striplines,
but the directivity is bad in high frequency ?
can any one help me?
is there any useful information about the coupler

 

[Ghost Tweaker]

Re: help me on coupler

If you have Agilent ADS you can use the passvie circuits designguide. Very useful.

 

[northguy]

Re: help me on coupler

yeah,@ds can help a lot

 

[Kit-the-great]

Usually, the directivity of the coupler depends on the number of stages. The common advice: increase number of stages and use the stages with high Q.

Best regards,
Kit-the-great

 

[AL0117]

Re: help me on coupler

Search the forum for:
"Microwave Engineering", by David M. Pozar (chapter7)
and
"Microwave Filters, Impedance Matching Networks and Coupling Structures" by Mathei, Young and Jones (chapter 13),

These are the Bible for coupler structures. You will find all the needed information there.

rgds, Al

 

[qiang]

Re: help me on coupler

i use two stages .
,the dificulty is that i can't find the way from the odd/even mode impendence to the structure .

and i use hfss to simulate it .the result is that the directivity is bad in the high frequency and in practice it is bad too
i refered asome book ,but it's the same question that can't find the way to strcture
and now they let me to disign a coupler of 5DB. i think the directivity is very difficulat for me
and i use strips in two side of the dielctic,to this structure ,i find no way to the practise .
is can i only find the crect design with hfss by much times change of the structure??

 

[BigBoss]

Re: help me on coupler

This part of a book is very valuable for these kind of applications..

 

[qiang]

Re: help me on coupler

is there ebook?