Agilent Technologies 89441A manual To measure signal to noise ratios

Page 22

Making Simple Noise Measurements

To measure signal to noise ratios

1Select the baseband receiver mode and initialize the analyzer:

Press [Instrument Mode] [receiver] [RF section (0-10 MHz)]. Press [Preset].

2Supply a signal from the internal source:

Connect the SOURCE output to the INPUT with a BNC cable.

Press [Source], [source on], [sine freq], 5, [MHz]

3Place the marker on the signal peak:

Press [Marker⇒ ], [marker to peak] or

Press [Shift], [Marker]

4Select video averaging: Press [Average], [average on]

5Turn on the carrier-to-noise marker:

Press [Marker Function], [band power markers], [band pwr mkr on], [power ratio C/N].

6Press [MarkerEntry]

Rotate the knob to move the measurement band from the signal to a noise area.

The display should appear as below. The grid lines have been turned off to highlight the band power markers.

Measured noise band

The diamond shaped marker provides a reference point

Carrier to noise ratio

The value indicated in the lower left corner of the display reflects the difference between the marker level at the carrier peak and the total noise within the band markers.

2-4

Image 22

Contents Agilent Technologies 89441A Getting Started Guide Analyzer at a Glance Iii Front PanelThis page left intentionally blank Saftey Summary Fuses Safety Symbols Notation Conventions This Book This page left intentionally blank Table of Contents General Tasks XiiUsing Online Help To learn about online help Enter the online help system Press HelpTo display help for hardkeys and softkeys To display a related help topic To select a topic from the help index Page Making Simple Noise Measurements To measure random noise Start an averaged measurementTo measure band power Turn on the band power markersTo measure signal to noise ratios Turn on the carrier-to-noise markerCarrier-to-noise ratio normalized to one Hertz Page Using Gating to Characterize a Burst Signal To Use Time Gating Display should now appear as shown belowSet up the time gating and examine the first burst Configure the display and the measurementExamine the second burst Page Measuring Relative Phase To measure the relative phase of an AM signal Measuring Relative Phase To measure the relative phase of an PM signal Zero the offset marker on the carrierCharacterizing a Filter Have option AY7 To set up a frequency response measurementIf section for network measurements Press Auto Scale To use the absolute marker To use the relative marker To use the search marker To display phase Specify phase data for the second traceTo display coherence Activate the second trace and select a coherence measurementGeneral Tasks To set up peripherals General Tasks To save data with an internal or RAM disk To recall data with an internal or RAM disk Press ReturnTo format a disk Define a constant To create a math functionDefine a math function Press Math, define F1 To use a math function To display a summary of instrument parameters Press measurement state or input/source statePage Preparing the Analyzer for Use Preparing the Analyzer for Use To chassis ground Analyzer cabinet can subject the operator to lethal voltages Power if it is damaged To do the incoming inspectionPreparing the Analyzer for Use To connect the sections Preparing the Analyzer for Use To install the analyzer To change the if section’s line-voltage switch SelectTo change the RF section’s line-voltage switch To change the if section’s fuse To change the RF section’s fuse RF SectionTo connect the analyzer to a LAN Internet protocol address ReturnTo connect the analyzer to a serial device To connect the analyzer to a parallel deviceTo connect the analyzer to an Gpib device To connect the analyzer to an external monitorTo connect the optional keyboard Set the if section’s power switch to on lConnect the other end of the keyboard cable to the keyboard To connect the optional minimum loss pad To clean the screen To store the analyzerTo transport the analyzer Electricity which can damage electronic componentsIf the if section will not power up If the RF section will not power up If the analyzer’s stop frequency is 10 MHz Page Index Basic HT Gpib SNR Dqpsk HTQAM SNR HTSee also traces FSK Gpib HTGpib LAN Manuals, for this product HT See LAN QAM HT RAMRPG See knobSource LED Sync not Found HT TdmaPSD HT EXT Trigger LED HTVSB Page Agilent 89400-Series Documentation Roadmap Need Assistance?