How to convert inductor into microstip?

[John_li]

Hi all,
I want to improve 5.8GHz LNA stability and serial an inductor between source and ground,for example L=1.4nH,how can i convert it into microstrip(Er=4.3,H=1mm,T=0.035mm,FR4material),how can i do it?any formula and tell me step by step?another hand,any tools that directly convert it?ADS is OK.
Thank you,

 

[Kohi_boy]

Maybe you can try a add A Shunt Stub of +j Y, Where Y = 1 / Z, and Z = wL.

 

[radiohead]

The input impedance of a shorted microstrip is something like \[jZ_0 \sin (\vartheta )\], where \[Z_0\] is the characteristic impedance of the microstrip and \[\vartheta\] is the electrical length (in phase) of the microstrip. Both can be calculated from a microstrip calculator like TXLine, or following the link below:

Microstrip Analysis/Synthesis Calculator

 

[tyassin]

Hi

Usually you also need a via to ground the "source". This is sometimes enough to add some stability.

regards

 

[John_li]

Thanks for all of reply.if i want to use a via instead of 1.4nH for 2GHz,what size is it?

 

[byteptr]

All responses are OK, and may be you already know, but FR4 isn't the better choice for MW and high Q circuits.
Good Luck