Re: About Balun
BalUn is a device to transfer the energy from Balanced-to-Unbalanced
(or vice-versa) configuration. Differential amplifiers , dipol antennas , mostly mixers etc use Balun.
For instance 50 Balanced input impedance can be converted 50 single ended Unbalanced input/output.
Additional to , it may serve a impedance matching function but it's not neccesary.
Principally, it serves balanced-unbalanced transforming between the devices.
There are many types of Balun such as L-C , Marchand, Transmission Line Balun, transformer with grounded seconder etc.
Unfortunately, there isn't so much book on this subject, only some papers and company app.reports.
A Balun can not be neglected if it's in a circuit.
Regards