Agilent Technologies E7401A, E7402A, E7403A, E7404A, E7405A Tracking Drifting Signals

Chapter 1 27

Making Basic Measurements

Tracking Drifting Signals

Tracking Drifting Signals

The signal track function is useful for tracking drifting signals that

drift relatively slowly. To place a marker on the signal you wish to

track, use Peak Search. Pressing FREQUENCY, Signal Track (On) will

bring that signal to the center frequency of the graticule and adjust the

center frequency every sweep to bring the selected signal back to the

center. A quick way to perform the PeakSearch, FREQUENCY,

Signal Track, SPAN key sequence is to use the Span Zoom key in the

SPAN menu.

Note that the primary function of the signal track function is to track

unstable signals, not to track a signal as the center frequency of the

analyzer is changed. If you choose to use the signal track function when

changing center frequency, check to ensure that the signal found by the

tracking function is the correct signal.

Tracking Signal Drift Example 1:

Use the signal track function to keep a drifting signal at the center of

the display and monitor its change.

This example requires a signal generator. The frequency of the signal

generator will be changed while you view the signal on the display of

the analyzer.

1. Connect a signal generator to the ana lyzer input.

2. Set the signal generator frequency to 300MHz with an a mplitude of

−20 dBm.

3. Set the analyzer as follows:

a. Press Preset, Factory Preset (if present).

b. Set the Y-Axis Units to dBm by pressing AMPLITUDE, More,

Y-AxisUnits, dBm .

c. Set the resolution bandwidth to the spectrum analyzer coupling

by pressing BW/Avg, Resolution BW (SA). See Figure 1-17.

d. Set the center frequency to 300MHz by pressing FREQUENCY,

Center Freq, 300, MHz.

Contents

Main Signal Analysis Measurement Guide Agilent Technologies EMC Series Analyzers Notice Safety Information Warrant y LIMITATION OF WARRANTY EXCLUSIVE REMEDIES Where to Find the Latest Informa tion Page Contents Page What is in This Chapter Test Equ ipm ent Comparing Signals Signal Comparison Example 1: Page Signal Comparison Example 2: Page Resolving Signals of Equal Amplitude Resolving Signals Example: Page Page Resolving Small Signals Hidden by Large Signals Resolving Signals Example: Page Page Making Better Frequency Measurements Better Frequency Measurement Example: Page Decreasing the Frequency Span Around the Signal Decreasing the Frequency Span Example: Page Page Tracking Drifting Signals Tracking Signal Drift Example 1: Page Page Tracking Signal Drift Example 2: Page Page Page Measuring Low Level Signals Measuring Low Level Signals Example 1: Page Measuring Low Level Signals Example 2: Measuring Low Level Signals Example 3: Page Measuring Low Level Signals Example 4: Page Page Identifying Distortion Products Distortion from the Analyzer Identifying Analyzer Generated Distortion Example: Page Page Third-Order Intermodulation Distortion Identifying TOI Distortion Example: Page Page Page Measuring Signal-to-Noise Signal-to-Noise Measurement Example: S/N 70 dB/Hz10 30 kHz()log+ 25.23 dB30 kHz()== Making Noise Measurements Noise Measurement Example 1: Page Page Page Page Noise Measurement Example 2: Noise Measurement Example 3: Page Page Demodulating AM Signals (Using the Analyzer As a Fixed Tuned Receiver) Demodulating an AM Signal Example 1: Page Page Page Page Page Demodulating FM Signals Demodulating a FM Signal Example: Page Page Page Page Whats in This Chapter Required Test Equipment Making Stimulus Response Measu rements What Are Stimulus Response Measurements? Using An Analyzer With A Tracking Generator Stepping Through a Transmission Measurement Page Page Page Page Tracking Generator Unleveled Condition Measuring Device Bandwidth Page Page Measuring Stop Band Attenuation Using Log Sweep Page Page Page Page Making a Reflection Calibration Measurement Example: Reflection Calibration Measuring the Return Loss Chapter 2 87 VSWR 110 Making Complex Measurements Making a Reflection Calibration Measurement -----------------------= Table 2-1 Power to VSWR Conversion + 110 Demodulating and Listening to an AM Signal Demodulating and Listening to an AM Signal Example 1: Demodulating and Listening to an AM Signal Example 2: