Download Lab-05 Spectrum Analyzer Introduction

Laboratory
5
Spectrum Analyzer
Wireless Systems
TLEN 5830
Wireless Systems
This Lab introduces spectrum analyser operations and miscellaneous additional laboratory
equipment and procedures.
Lab-05 Spectrum Analyzer Introduction:
Spectrum Analyzer: Measures the magnitude of an input signal versus frequency.
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The primary use is to measure the power of the spectrum of known and unknown
signals
The input signal is electrical (volts)
The display of a spectrum analyser has frequency on the horizontal axis and amplitude
displayed on the vertical axis.
By analyzing the spectra of electronic signals, the dominant frequency, power, distortion,
harmonics, bandwidth, and other spectral components of a signal can be observed that are not
easily detectable in time domain waveforms.
In contrast, an oscilloscope allows observation/measurement of constantly changing signal
voltages usually as a two-dimensional plot of one or more signals as a function of time.
Equipment
TLEN 5830 Wireless Systems
Lab-05 Spectrum Analyzer
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Function Generator: A function generator is used to generate repetitive waveforms based on
electrical concepts. Most function generators are capable of producing sine waves, square
waves, and triangle waves. In this lab, the function generator will be used to generate AC
output in a sine wave, the same as a carrier signal for a traditional telecommunications
connection.
Agilent 33120A 15 MHz Function/Waveform Generator
Spectrum Analyzer: A spectrum analyzer is used to display a graphic representation of the
spectral components of a frequency. The range of frequencies it represents can be adjusted,
allowing inspection of a wide range of frequencies. It can also be used to find ‘peaks’ in the
spectrum, or strong frequencies and sidebands
Agilent (Keysight Technologies) N9344C Handheld Spectrum Analyzer (HSA)
TLEN 5830 Wireless Systems
Lab-05 Spectrum Analyzer
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Cables and Connectors: Used to connect the voltage source (input) to the analysis equipment
(the spectrum analyzer). For this lab, one particular type of unique connecter is used: a Bayonet
Neill-Concelman (BNC) (also known, most sources agree erroneously, as a British Naval
Connector).
Lab-05 Exercises
Procedure
1. Generate a baseband signal of 15 MHz, with 5 Vpp amplitude, by following these steps:
Turn on the power on the Agilent function generator. Ensure you are on
frequency view by pressing FREQ button. The frequency will now show in the
display window.
Change the frequency by either rotating the dial or entering the following sequenceENTER NUMBER, the appropriate number keys (which share their button with other
functions), and the unit KHz, MHz, etc.). Frequency is now set.
Switch to the amplitude view, by pressing AMPL. The amplitude of the baseband signal
is now shown in the same window as frequency was. Adjust the amplitude by either
rotating the dial, or entering the desired number (ENTER NUMBER, appropriate number
keys-in this case 5, and MHz/Vpp).
Your baseband signal function generator should now be generating a signal whose form
is that of sine wave of 15 MHz frequency with 10V peak-to-peak amplitude. Ensure you
are satisfied this is the case by using the FREQ and AMPL keys to double-check the
frequency and amplitude.
Vrms and Vpp.
TLEN 5830 Wireless Systems
Lab-05 Spectrum Analyzer
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