Product Specification

MF602F

Data sheet subject to change without notice

RDPS-MF017(R1)03/04/2002

SHEET 8 OF 11

4.4.2 : Return loss :

Return loss measure the amount of energy that is lost due to reflection which resulted

from impedance mismatching at the interface. Return loss is essentially defined as the

ratio of the power incident upon a given transmission system to the power reflected

caused by impedance mismatch with respect to reference impedance at the interface

between source and device.Return loss figure are a function of the impedance of the

circuit involved and are therefore frequency dependent.

These impedance must be closely maintained in order to reduce the possibility of

undesirable reflection and echoes which in long distance circuit the telephone user or

destroy the data being sent.To perform the return loss test ,open ,short, load calibration

must be done prior measurement while the LCZ impedance Analyzer being selected in

impedance mode. Return loss is general expressed in decibels. General Return loss

equation as below:

Return loss = 20 log

Z

Where Z

Z

The test setup is shown in drawing below:

ZL

LPF

Equipment

ZL

Phone

Line

Load#1 LPF

Load#4 LPF

Remote POTS Splitter

Return loss reference

impedance

Test