* '''Matching Circuits:''' The input and the output must be matched to 50ᘯ for optimal performance. Every device has a Input and output impedance. These are the impedances looking from input and output respectively. For maximum transfer of power all the impedances of connecting components or tracks or wires should be same. If there is a mismatch the signals may get reflected and damage the amplifier. For more reading one can read Transmission lines. <br \>

If there is a mismatch between input of a connected device and output of the other device and matching circuit has to be designed for impedance matching. Example is shown in the following figure.

== Power Amplifier (PA) ==