Agenda l l l Spectrum Analyzer Basics Overview

Agenda l l l Spectrum Analyzer Basics Overview: l What is spectrum analysis? l What measurements do we make? Theory of Operation: l Spectrum analyzer hardware Specifications: l Which are important and why? Features l Making the analyzer more effective Summary Appendix 1

Overview Types of Tests Made . Modulation Noise Distortion Spectrum Analyzer Basics 2

Overview Frequency versus Time Domain Amplitude (power) y nc e u q fre tim e Time domain Measurements Spectrum Analyzer Basics Frequency Domain Measurements 3

Overview Different Types of Analyzers Fourier Analyzer A Parallel filters measured simultaneously LCD shows full spectral display f 1 Spectrum Analyzer Basics f 2 f 4

Overview Different Types of Analyzers Swept Analyzer A Filter 'sweeps' over range of interest LCD shows full spectral display f 1 Spectrum Analyzer Basics f 2 f 5

Theory of Operation Spectrum Analyzer Block Diagram RF input attenuator IF gain IF filter detector mixer Input signal Log Amp Pre-Selector Or Low Pass Filter local oscillator video filter sweep generator Crystal Reference Spectrum Analyzer Basics CRT display 6

Theory of Operation MIXER Mixer f sig input RF IF LO f LO+ f sig f LO- f sig f LO Spectrum Analyzer Basics 7

Theory of Operation IF Filter IF FILTER Input Spectrum IF Bandwidth (RBW) Display Spectrum Analyzer Basics 8

Theory of Operation Detector DETECTOR amplitud e "bins" Positive detection: largest value in bin displayed Negative detection: smallest value in bin displayed Sample detection: last value in bin displayed Spectrum Analyzer Basics 9

Theory of Operation Video Filter VIDEO FILTER Spectrum Analyzer Basics 10

Theory of Operation Other Components LO SWEEP GEN RF INPUT ATTENUATOR Spectrum Analyzer Basics frequency LCD DISPLAY IF GAIN 11

Theory of Operation How it all works together fs 0 Signal Range 1 2 f LO- f s 3 (GHz) mixer LO Range f LO+ f s fs 0 IF filter 1 input fs 2 4 3 3. 6 5 6 detector 6. 5 3. 6 sweep generator f IF A LO f LO 0 4 3 5 3. 6 Spectrum Analyzer Basics 6 (GHz) 1 2 3 (GHz) f LCD display 6. 5 12

Theory of Operation Front Panel Operation Primary functions (Frequency, Amplitude, Span) Softkeys 8563 A SPECTRUM ANALYZER 9 k. Hz - 26. 5 GHz Control functions (RBW, sweep time, VBW) RF Input Spectrum Analyzer Basics Numeric keypad 13

Specifications 8563 A SPECTRUM ANALYZER 9 k. Hz - 26. 5 GHz Frequency Range ä Accuracy: Frequency & Amplitude ä Resolution ä Sensitivity ä Distortion ä Dynamic Range ä Spectrum Analyzer Basics 14

Specifications Frequency Range Low frequencies for baseband IF Measuring harmonics 50 GHz and beyond! Spectrum Analyzer Basics 15

Specifications Accuracy Absolute Amplitude in d. Bm Relative Amplitude in d. B Frequency Relative Frequency Spectrum Analyzer Basics 16

Specifications Accuracy: Frequency Readout Accuracy Typical datasheet specification: Spans < 2 MHz: +(freq. readout x freq. ref. accuracy _ + 1% of frequency span + 15% of resolution bandwidth + 10 Hz "residual error") Frequency Spectrum Analyzer Basics 17

Specifications Accuracy: Frequency Readout Accuracy Example Single Marker Example: 2 GHz 400 k. Hz span 3 k. Hz RBW Calculation: Spectrum Analyzer Basics -7 (2 x 10 9 Hz) x (1. 3 x 10 /yr. ref. error) 1% of 400 k. Hz span 15% of 3 k. Hz RBW 10 Hz residual error Total = = = + _ 260 Hz 4000 Hz 450 Hz 10 Hz 4720 Hz 18

Specifications Resolution: Resolution Bandwidth Mixer 3 d. B BW 3 d. B Detector Input Spectrum LO IF Filter/ Resolution Bandwidth Filter (RBW) Sweep RBW Display Spectrum Analyzer Basics 19

Specifications Resolution: RBW Type and Selectivity 3 d. B BW 60 d. B BW Selectivity Spectrum Analyzer Basics = 60 d. B BW 3 d. B BW 20

Specifications Resolution: RBW Type and Selectivity RBW = 1 k. Hz Selectivity 15: 1 RBW = 10 k. Hz 3 d. B distortion products 7. 5 k. Hz 60 d. B BW = 15 k. Hz 10 k. Hz Spectrum Analyzer Basics 21

Specifications Resolution: Residual FM "Smears" the Signal Spectrum Analyzer Basics 22

Specifications Resolution: Noise Sidebands Phase Noise Sidebands can prevent resolution of unequal signals Spectrum Analyzer Basics 23

Specifications Resolution: RBW Determines Measurement Time Swept too fast Penalty For Sweeping Too Fast Is An Uncalibrated Display Spectrum Analyzer Basics 24

Specifications Sensitivity/DANL Effective Level of Displayed Noise is a Function of RF Input Attenuation signal level 10 d. B Attenuation = 20 d. B Signal-To-Noise Ratio Decreases as RF Input Attenuation is Increased Spectrum Analyzer Basics 25

Specifications Sensitivity/DANL Sensitivity is the Smallest Signal That Can Be Measured Signal Equals Noise Spectrum Analyzer Basics 2. 2 d. B 26

Specifications Sensitivity/DANL For Best Sensitivity Use: H Narrowest Resolution BW H Minimum RF Input Attenuation H Sufficient Video Filtering (Video BW <. 01 Res BW) Spectrum Analyzer Basics 27

Specifications Dynamic Range +30 d. Bm MAXIMUM POWER LEVEL -10 d. Bm MIXER COMPRESSION -35 d. Bm THIRD-ORDER DISTORTION LCD-DISPLAY MEASUREMENT SECOND-ORDER RANGE -45 d. Bm DISTORTION RANGE 145 d. B 80 d. B SIGNAL/NOISE RANGE 105 d. B 0 d. Bc SIDEBANDS SIGNAL /3 rd ORDER DISTORTION 80 d. B RANGE INCREASING SIGNAL/ 2 nd ORDER DISTORTION SIGNAL/NOISE BANDWIDTH OR 70 d. B RANGE SIDEBANDS ATTENUATION 60 d. Bc/1 k. Hz -115 d. Bm (1 k. Hz BW & 0 d. B ATTENUATION) Spectrum Analyzer Basics MINIMUM NOISE FLOOR 28

Features Modulation Measurements: FFT Swept Frequency Domain FFT Frequency Domain LIN 10 d. B/ MARKER 1 k. Hz -26 d. Bc CENTER 100 MHz Spectrum Analyzer Basics MARKER 1 k. Hz -26 d. Bc SPAN 10 k. Hz CENTER 100 MHz SPAN 0 Hz 29

Features Modulation Measurements: AM/FM Detector with Speakers 8563 A Spectrum Analyzer Basics SPECTRUM ANALYZER 9 k. Hz - 26. 5 GHz 30

Features Noise Measurements: Noise Marker & Video Averaging 8563 A SPECTRUM ANALYZER MKR 1. 025 MHz -135. 75 d. Bm/Hz Spectrum Analyzer Basics 9 k. Hz - 26. 5 GHz AVG 10 31

Features Stimulus Response: Tracking Generator Receiver Source DUT Spectrum Analyzer RF in CRT Display IF DUT LO TG out Tracking Adjust Tracking Generator Spectrum Analyzer Basics 32