how to make stripline
I have been looking around and never understand what is a series stub. I understand design using smith chart, I just don't get the physical structure using stripline or microstrip.
Thanks
http://sss-mag.com/pdf/msmatch.pdf
Don't try to use a series stub matching network when working with microstrips. It is much easier to implement using shunt stubs instead. Physically it is just a piece of microstrip conductor at a 90° angle to the microstrip line.
As YoungEng said is better shunt stub .
Working frequency ?
Bandwith ?
Sustrate type ?
Both ( series and shunt) are essential if BW requirement is more.
Simple series stubs are not possible in microstrip or stripline, as you can make a series structure in the top trace, but not in the ground plane underneath.
Never the less, there are a number of series-like structures that can be used in stripline/microstrip. With some creativity, these can be included in matching structures. Look at Microwave Filters Impedance-Matching Networks, and Coupling Structures by Matthaei, Young, and Jones. On pages 219-228 there are a lot of depictions of such structures, although the models shown there are only accurate for TEM such as stripline, and not microstrip (which have εeven ≠εodd).
Rich
You can do a lot with a series stub. With a 90degree phase shift at a given impedance you can transform to nearly any impedance.
Here is a spreadsheet that will show you how to make them:
http://www.microwaves101.com/downloads/Xfmr101Rev3.xls
You can use it to make as many sections as you want. It only covers real impedances but you could tune it in your simulator for a complex match.[/url]
The formula for a single 90 degree line is simple and as follows:
ZT=(ZL*ZS)^0.5