variants of lc baluns

[peol]

I ave found (at least) two variants of discrete lc baluns. The basic one with two components (LC and CL) in each branch and one with three components in each branch (see picture: https://obrazki.elektroda.pl/3405043700_1383300367.jpeg). What is the reason of chosing one or the other? Advantages/disadvantages?

 

[FvM]

Generally speaking, the "two components" variant will not necessarily achieve the intended impedance matching. If it's a PA balun, you'll most likely want an additional low-pass filter, so the "two components" balun will give sufficient degrees of freedom.

 

[BigBoss]

They are used for wider bandwidth but their precision is less than original one.

 

[peol]

Generally speaking, the "two components" variant will not necessarily achieve the intended impedance matching. If it's a PA balun, you'll most likely want an additional low-pass filter, so the "two components" balun will give sufficient degrees of freedom.

I guess you mean "three omponents" balun in the last sentence? Both versions transforms a real impedance to another real impedance, do you mean that the "three omponents" balun can match complex loads as well? I thought the balun only transferred the real impedance and that the potential imaginary part of the load was taken care of by an added matching component/network.