User`s guide

Getting Started with Return Loss A Background to Return Loss Measurement

36 Agilent 81610A/11A/12A/13A/14A Return Loss Module, Fifth Edition

A Background to Return Loss

Measurement

Measuring the Reflected Power from a

Component with Known Reflection Factor

First, attach a component with a known reflection factor in place of

the DUT, and measure the power reflected. This is component is called

the reflection reference.

Figure 29 Measuring the Power from a Component with a Known Reflection Factor

This measured power from the reflection reference is called P

Ref

The following two components are recommended for use as a

reflection reference:

• the Agilent 81610CC Reference Cable, or

• the Agilent 81000BR Back Reflector.

NOTE Note you can only measure the Front Panel Delta if you use a

Reflection Reference Cable.

The reflection factor for the component is called R

. Normally the

return loss for the component (RL

) is specified, but these values are

Reflection

Reference

ref

Agilent 81610A

Reflectivity

5/ 10 5log– 10

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