how to design bias circuit using radial stub

[naveeng]

radial stub design

dear frns..

one of most commonly used method for designing bias circuit is to use a radial stub followed by high impedance line...

so frns can any one explain how to design radial stub, with center freq = 5GHZ,
for bias circuit design....if any oe know about ieee paper regarding this radial stub design pllz mention the title of the paper

thanking u....

 

[fernetbranca]

I've read an article at microwaves101 (.com) mentioning the radial stub bias technique, but they don't give any formulas.
I would try CAD tuning...

The high impedance line you mention is a quarter wave transmission line (at 5GHz), followed by the radial stub (low impedance) above. You should tune its parameters (I think there are just 3) to see if you get the bandwidth you need. Don't forget to calculate the current level passing through the high impedance line, because it could be(and surely will be) VERY thin.

Look at Filtronic's website, they have application notes of amplifiers using radial stubs.

Regards,
FernetBranca