Balun analysis and design procedures

Hi all,

Could someone help me to understand this balun cicuit.

Could you please get me design procedure for this circuit.

Thanks,
Sridhar

My quick understanding:

-balun LC-CL classical architecture (+90 deg on one branch, -90 deg on other branch) made by: L122/C122, L132/C131 - 1.5pF and 18 nH
-single end matching network: L123/C123
-DC blocks: C125, C124
-Differential matching network: L121/L131/C121

I have not made any calculation yet, but it seems reasonable.

I hope it can help.

Mazz

Hi Mazz

Thanks a lot,

My idea is to implement this in a substrate material of Er=9.4 and Tloss= 0.0014.
Operating frequency is 902 to 928 Mhz.

Do you have some Idea on this also,

Thanks,
Sridhar.

Usually losses of passives at this freqs are dominant (unless you have to design long microstripes or complex distributed circuits), so the use of an expensive substrate has no reason to happen. Normal FR4 is OK.
I hope it can help.
Mazz