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[[File:Polarization2.png|center|frame]]
Now, the polarization of any antenna is simple the polarization of electromagnetic waves radiated by that antenna. The reason why polarisation of antenna is so important is it is useful in determining the losses while making the link budget.
=== Balun ===
Balun is not necessarily a characteristic of an antenna. It is more of an additional component in some antenna. We suggest that you read about various types of antennas before reading about balun as it is used only for designing an antenna. Balun is derived from the expression ‘'''bal'''anced to '''un'''balanced’. It simply converts an unbalanced signal to a balanced signal. To put it very simply, a coaxial cable which has outer coating as ground (zero potential) and inner core as signal (some voltage V) is an unbalanced signal. While a twisted cable pair in which one wire has potential V and other has potential -V is a balanced signal. Some antennas such as monopole work when unbalanced signal are fed to it. On the other hand dipole antenna require unbalanced signal (+V, -V). Transmitting circuits usually generate unbalanced signal. Hence to convert unbalanced signal to balanced signal baluns are required. <br \>
There are numerous types of baluns. Some use transformers and autotransformers, some acts as RF choke. Ham enthusiasts often use ‘delay line type’ baluns. They are nothing but introducing delay using transmission lines and using it to balance a signal.
