Agilent Technologies 8156A manual Setting Up the Software, Editing the Setup

Using your Attenuator as a Variable Back Reflector

Setting Up the Software

4.2 Setting Up the Software

There are four factors that influence the back reflection of the attenuator. These are

1.the insertion loss of the attenuator (INS LOSS),

2.the return loss of the attenuator (RL INPUT),

3.the reference return loss you are using (RL REF), and

4.the filter attenuation.

The return loss (RL) is calculated according to the equation



RL ( dB) = –10 log  10



–R L In pu t( d B)

-------------------------------------

10

		–----R----L----I--n----p---u----t--(--d----B---)-			–----(--2----(--A----t--t--(---d---B----)----+-----I--n----s---L---o----s---s--(---d---B----)--)----+-----R----L----R----e---f---(--d---B----)--)-	
	1 – 10	10		10	10	
+ 						
						

You edit the values for the insertion loss, the reference return loss, and the return loss of the attenuator while you are setting up the application.

You edit the value for the return loss while the application is executing. The instrument calculates and sets the required value for the filter attenuation.

Editing the Setup

Before you start setting up the back reflector application, you may need to measure the following values, if you do not already know them:

•The insertion loss of the instrument (see “Example, Setting the Calibration” on page 42,

•The return loss of the instrument (with the output properly terminated), and

•The reference return loss value.

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