Insertion loss

Especially for high-frequency signals, it becomes smaller when the input signal is output through the transmission line. The parameter that indicates the degree of this decrease is called insertion loss.
It is defined as the ratio of the output signal to the input signal, and the unit is mainly dB.
Electric signals are reduced by being converted into heat, and the causes are resistance loss in the metal of the transmission line and dielectric loss that turns into heat generation in the insulating material. In addition, the signal becomes smaller due to reflection, so stabilization of the characteristic impedance is important for reducing insertion loss, especially for parts such as connectors that have a short connection distance.