Measuring Electrical Length and Phase Distortion

Electrical Length

The analyzer mathematically implements a function similar to the mechanical “line stretchers” of earlier analyzers. This feature simulates a variable length lossless transmission line, which you can add to or remove from the analyzer’s receiver input to compensate for interconnecting cables, etc. In this example, the electronic line stretcher measures the electrical length of a SAW filter.

Phase Distortion

The analyzer allows you to measure the linearity of the phase shift through a device over a range of frequencies and the analyzer can express it in two different ways:

ndeviation from linear phase

ngroup delay

Measuring Electrical Length

1. Connect your test device as shown in Figure 2-33.

NETWORK ANALYZER

DEVICE UNDER TEST

Figure 2-33. Device Cmmections for Measuring Electrical Length

2.Press w and choose the measurement settings For this example, the measurement settings include reducing the frequency span to eliminate under sampled phase response.

Press the following keys as shown:

/:...; ........................J,;......,.,.,.....,.....,..,.,.,.,.,.,.,.........; ,.,./ %.............. _ ::,:.::.,..

IMeas] ~~~~~~:,~~~~~~~~~

. - .: / -:. 7;;-.............. . .... ...............z .. .. ~........w..;..~..................v : ... ...a.. .. .~

i .i.::

Lcenter]@LM_U

 

EEa cg@

LMenu)~~~~O(;;r)

B gfgg&(

.i.... i

................:..... . .... .

Cm, ~~~~~.

..~..~~~~~~~~~~.~~~:...:.:..:.: _,.:.:.:.:.:.:.:..~:.:.:.,.:.,,:.:.:.: .,,/

You may also want to select settings for the number of data points, averaging, and IF bandwidth.

240 Makine Msasursments

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HP 8753E manual Measuring Electrical Length and Phase Distortion