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Making Measurements
Using Ripple Limits to Test a Device
Figure 1-66 Filter Pass Band Before Ripple Test
Setting Up Limits for Ripple Testing
This section instructs you on setting up the ripple test parameters. You must set up the
analyzer to check the DUT at the correct frequencies and compare the measured values
against the maximum allowable ripple value for each frequency band. To do this, you set
up individual frequency bands. You define the stop and start frequency and the maximum
allowable ripple value of each frequency band. You may set up as many as 12 frequency
bands for testing ripple. The frequency bands are combi ned i n a list that is displayed while
the ripple frequency bands are being edited.
In this example, we will create one ripple limit (or frequency band) that spans the entire
pass band from 500 MHz to 3.0 GHz. We will also create two additional frequency bands
that when merged, will span the pass band with tighter limits. Using the Ripple Edit
Menu, we will create a ripple limits list on the analyzer that is similar to the following
table.
Notice that Frequency Band 1 overlaps in frequency the remaining frequency bands.
Whereas, Frequency Bands 2 and 3 are separate bands that cover the same span of
frequency. This can be done to put tig hter li mits ov er narr ower f re quency spa ns wi thin the
bandpass or to customize the ripple test to meet your specific requirements.
Table1-3 Ripple Limits for Ripple Test Example
Frequency
Band Minimum
Frequency Maximum
Frequency Maximum
Ripple
1 500 MHz 3.2 GHz 2.0 dB
2 500 MHz 1.85 GHz 1.3 dB
3 1.85 GHz 3.2 GHz 1.3 dB