Synthetic Instruments: Concepts and Applications (eBook)

Cover 1
Contents 4
Foreword 12
Plan of this Book 13
Chapter Outline 14
Preface 16
Acknowledgments 18
What’s on the CD-ROM? 20
Chapter 1. What is a Synthetic Instrument? 22
History of Automated Measurement 22
Genesis 23
Modular Instruments 25
Synthetic Instruments Defined 26
Synthesis and Analysis 27
Generic Hardware 27
Advantages of Synthetic Instruments 32
Eliminating Redundancy 32
Measurement Integration 34
Measurement Speed 35
Longer Service Life 36
Synthetic Instrument Misconceptions 36
Why not Just Measure Volts with a Voltmeter? 37
Virtual Instruments 37
Analog Instruments 40
Chapter 2. Synthetic Measurement System Hardware Architectures 42
System Concept„The CCC Architecture 42
Signal Flow 43
The Synthetic Measurement System 44
Chinese Restaurant Menu (CRM) Architecture 44
Parameterization of CCC Assets 46
Architectural Variations 47
Compound Stimulus 48
Simultaneous Channels and Multiplexing 49
Hardware Requirements Traceability 55
Chapter 3. Stimulus 56
Stimulus Digital Signal Processing 56
Waveform Playback 57
Direct Digital Synthesis 58
Algorithmic Sequencing 60
Synthesis Controller Considerations 62
Stimulus Triggering 63
Stimulus Trigger Interpolation 64
The Stimulus D/A 65
Interpolation and Digital Up-Converters in the Codec 66
Stimulus Conditioning 67
Stimulus Conditioner Linearity 68
Gain Control 68
Adaptive Fidelity Improvement 70
Reconstruction Filtering 71
Stimulus Cascade„Real-World Example 72
Chapter 4. Response 76
Response Signal Conditioning 76
Input Protection 76
Response Linearity and Gain Control 77
Adaptive Techniques 78
The Response Codec 79
Fidelity and Measurement Accuracy 79
Ideal Quantization 81
Codec Headroom 81
Headroom Trade-off and System Fidelity 82
Response Digital Signal Processing 83
Waveform Recorder and DSP 83
Matched Filter Demodulator 85
Response Trigger Time Interpolator 87
Response Cascade„Real-World Example 87
Chapter 5. Real-World Design: A Synthetic Measurement System 90
Universal High-Speed RF Microwave Test System 90
Background 90
Logistical Goals 91
Technical Goals 91
RF Capabilities 91
System Architecture 92
Microwave Synthetic Instrument (TRM1000C) 92
Supplemental Resources 95
DUT Interface 95
Product Test Adapter Solutions 96
Calibration 96
Primary Calibration 96
Operational Calibration 97
Software Solutions 97
Test Program Set Developer Interface 98
TRM1000C Software 98
Conclusions 99
Chapter 6. Measurement Maps 102
Measurement Abstraction 104
General Measurements 106
Abscissas and Ordinates 107
The Measurement Function 107
Canonical Ordinate Algorithms 109
Multidimensional Measurements 109
Domains 110
Measurement Maps 111
Ports and Modes 113
DUT Modes as Abscissas 115
Ports as Abscissas 115
Map Manipulations 116
Problems with Hysteresis 120
Stimulus and Response 121
Inverse Maps 121
Accuracy Advantages of Inverse Maps 123
Problems with Inverse Maps 124
Calibration Strategy and Map Manipulations 125
Canonical Maps 126
Sufficiency of the Stimulus Response Measurement Map Stance 128
Processing a Measurement 129
The Basic Algorithm 130
Chapter 7. Signals 136
Kinds of Signals 137
Coding, Decoding, and Measuring the Signal Hierarchy 138
Decoding Method Abscissas 139
Direct Real Analog Baseband Signals 140
Digital Coded Baseband 142
Analog Coded Baseband 142
Bandwidth 143
Bandpass Signals 146
Bandpass Sampling 148
Image Rejection 151
Interference and Images 152
I/Q Sampling 153
Broadband Periodic Signals 154
Chapter 8. Calibration and Accuracy 158
Metrology for Marketers and Managers 158
Measurand 159
Accuracy and Precision 161
Test versus Measurement 162
Introduction to Calibration 164
Reference Standards 164
Uncertainty Analysis 164
Stimulus Calibration 165
Overall Strategy for Stimulus Calibration 166
Using Interpolation to Invert a Map 166
Interpolation Example 168
Sampling Interval versus Resolution Confusion 170
Ordinate Quantization and Precision 174
De-Embedding Calibration Objects 175
De-Embedding Dimensionality and Interpolation 177
Abscissa De-Embedding 177
Chapter 9. Specifying Synthetic Instruments 178
Synthetic Instrument Definition and XML 179
Why XML ? 180
ATML 183
Why Not SCPI, ATLAS,ƒ? 183
Introduction to XML 185
Automatic Descriptions 185
Not a Script 187
XML Basics 188
Synthetic Measurement Systems and XML 189
Describing the Measurement with XML 190
Defining an Instrument 192
Calibration Strategy Example 196
Functional Decomposition and Scope 198
Measurement Parameters„A Hazard 200
Describing the Measurement System with XML 201
Describing Measurement Results with XML 205
Column and Array Data 206
Self-Documenting Features 206
Arrays as Elements 207
SQL Database Concepts and Data Objects 208
HDF 209
Chapter 10. Synthetic Instrument Markup Language: SIML 212
A DTD for Measurement Description 213
More SIML Details 216
Locked Abscissas 217
Banded Abscissas 219
Constraints 222
Modulation 223
Ordinate Modifiers: Averaging and Statistical Manipulations 224
Chapter 11.Ten Mistakes in Synthetic Measurement System Design 226
Fixing Performance or Functionality Shortfalls Exclusively by Adding Hardware 226
Fixing Hardware Mistakes with Software 228
Adding Modes or Features Dedicated to Specific Measurements 228
Designing Synthetic Instruments Procedurally 229
Meeting Legacy Instrument Specifications 230
Developing Stimulus Separate from Response 232
Not Combining Measurements 233
Hardware Modularity as a Distraction 233
Bad Lab Procedure 234
Fear of Change 235
Acronym Glossary 238
Basic SIML DTD 242
Bibliography 244
Books 244
Periodicals 245
Conference Papers 245
About the Author 246
Index 248