Agilent Technologies E7401A, E7402A, E7403A, E7404A, E7405A Measuring Low Level Signals Example 3:

Chapter 1 37

Making Basic Measurements

Measuring Low Level Signals

9. Place the signal at center frequency by pressing Peak Search,

Marker→, Mkr→CF.

10.Press BW/Avg, Res BW, and then ↓. The low level sign al appears

more clearly because the noise level is reduced. As shown in

Figure 1-29.

A # mark appears next to the Res BW annotation at the lower left

corner of the screen, indicating that the resolution bandwidth is

uncoupled. As the resolution bandwidth is reduced, the sweep time

is increased to maintain calibra ted data.

Figure 1-29 Decreasing Resolution Bandwidth

Measuring Low Level Signals Example 3:

Narrowing the video filter can be useful for noise measurements and

observation of low level signals close to the noise floor. The video filter

is a post-detection low-pass filter that smooths the displayed trace.

When signal responses near the noise level of the analyzer are visually

masked by the noise, the video filter can be narrowed to smooth this

noise and improve the visibility of the signal. (Reducing video

bandwidths requires slower sweep times to keep the analyzer

calibrated.)

Using the video bandwidth function, measure the amplitude of a low

level signal.

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

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

−80 dBm.

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: