In high frequency circuits, it is important to perform impedance matching between circuits.
Impedance matching is to match the output impedance of the sending side circuit, and the input impedance of the receiving side circuit in the signal transmission path.
By matching the impedance, the power on the sending side can be transmitted at the maximum to the receiving side.
Although a capacitor and inductor are used in the matching circuit, the actual capacitor and inductor are not ideal components, and a loss will be generated.
There is a Q to express this loss.
When the Q is higher, it shows that the capacitor and inductor have less loss.