INSERTION LOSS

Transmission feed line system performance plays an important

role in wireless network coverage. Insertion loss measurement

is one of the critical measurements used to analyze transmission

feed line installation and performance quality. 

In wireless communication systems, the transmit and receive

antennas are connected to the radio through coaxial cable

and/or waveguide transmission lines .

Insertion loss measures the energy absorbed by the transmission

line in the direction of the signal path in dB/meter or dB/feet.

Transmission line losses are dependent on cable type, operating

frequency and the length of the cable run. Insertion loss of a

cable varies with frequency; the higher the frequency, the

greater the loss.

In other words, 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 P_T and the power received by the load after insertion is P_R, then the insertion loss in dB is given by,