Agilent Technologies 8719ET, ES, 8720ET, 8722ET Measuring Other Transmission Characteristics

Quick Start: Learning How to Make Measurements

Learning to Make Transmission Measurements

Measuring Other Transmission Characteristics

Using the analyzer marker functions, you can derive several important filter parameters from the measurement trace that is shown on the analyzer display.

Measuring 3 dB Bandwidth.

The analyzer can calculate your test device bandwidth between two equal power levels. In this example procedure, the analyzer calculates the −3 dB bandwidth relative to the center frequency of the filter.

1.Press Marker and turn the front panel knob to move the marker to the center frequency position of the filter passband. An alternative method is to press

Marker Search SEARCH: MAX which should put you very close to the center of the passband.

You can also position the marker by entering a frequency location: for example, press

10.24 G/n .

2.Press Marker MKR ZERO to zero the delta marker magnitude and frequency (this sets the delta marker reference). The −3 dB points will be relative to this marker.

The softkey label changes to MKR ZERO Δ REF= Δ showing you that the delta reference point is the small Δ symbol.

3.Press Marker Search to enter the marker search mode.

4.Toggle WIDTHS on OFF to ON.

The analyzer calculates the −3 dB bandwidth, the center frequency and the Q (quality

factor) of the test device and lists the results in the upper-right corner of the display. Markers 3 and 4 indicate the location of the −3 dB points, as shown in Figure 2-5.

Figure 2-5 Example Measurement of 3 dB Bandwidth

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