Insertion loss
In telecommunications, insertion loss is the loss of signal power resulting from the insertion of a device in a transmission line or optical fiber and is usually expressed in decibels (dB). If the power transmitted to the load before insertion is PT and the power received by the load after insertion is PR, then the insertion loss in decibels is given by, I L ( d B ) = 10 log 10 P T P R {\displaystyle IL(\mathrm {dB} )=10\log _{10}{P_{\mathrm {T} } \over P_{\mathrm {R} }}} == Electronic filters == Insertion loss is a figure of merit for an electronic filter and this data is generally specified with a filter.