Product Specification

MF609A

Data sheet subject to change without notice

RDPS-MF038(R0)01/23/2002

SHEET 9 OF 12

4.5.3. 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:

4.5.3.1. Phone port return loss :

4.5.3.2. Line port return loss :

ZNL-r defined

Zoff defined