Insertion loss is the deficiency of signal power resulting from the insertion of a device in a transmission line or optical fiber. It is normally expressed in decibels (dB). Insertion loss is characterized as the loss that is apparent upon inserting the network to be measured between a given source and a given receiver. The insertion loss method comprises the measurement of the power loss because to the FUT insertion between a launching and a receiving framework, recently interconnected. Insertion loss is characterized as the proportion of the power in Rf over that accessible from the source generator.