Sampling oscilloscope: Difference between revisions

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Tektronix made oscilloscopes and plug-ins intended for sampling measurements.  
A sampling oscilloscope captures the time domain waveform at discrete time intervals using a [[Sampler|sampling circuit]]. These captured voltages are then either stored in an analog fashion (integrator circuits and CRTs) or digitized and processed digitally.
Through the 1960s, the sampling group at Tektronix was led by [[Al Zimmerman]].
 
A distinction is made between real-time and equivalent time sampling. Real-time sampling requires a sampling rate of at least twice the highest signal bandwidth to capture the signal without [https://en.wikipedia.org/wiki/Aliasing aliasing artifacts]. It is rare with analog oscilloscopes, but the method of choice for low to medium speed [[:Category:Digital storage scopes|digital storage oscilloscopes]], and allows for single shot waveform acquisition.
 
Equivalent time sampling requires repetitive signals but allows to capture a fast signal with a sampling rate much slower than the signal bandwidth. When talking about a "Sampling Oscilloscope" this approach is usually referred to. For digital instruments the term [[:Category:Digital Sampling scopes|"Digital Sampling Oscilloscopes"]] is used. However the lines are blurry, since many instruments utilizing sampling concepts switch between different acquisition modes depending on the timebase setting.
 
 
:{|
|-
| [[File:RealTimeSampling_Fig29_XYZs_of_Oscill.png|500px]] || [[File:EquivTimeSampling_Fig32_XYZs_of_Oscill.png|400px]]
|-
| style="text-align:center;"|Real-Time Sampling      || style="text-align:center;"|Equivalent Time Sampling
|-
|}
 
 
Equivalent time sampling is further divided into sequential, and [[random sampling]].
Instruments that have a random sampling mode usually also have a sequential sampling mode, e.g., the [[7T11]].
 
:{| style="width: 60%;"
|-
| [[File:RandomTimeSampling_Fig33_XYZs_of_Oscill.png|600px]] || [[File:SequentialTimeSampling_Fig34_XYZs_of_Oscill.png|600px]]
|-
| style="text-align:center;"|Random equivalent-time sampling: the sampling clock runs asynchronously with the input signal and the trigger.      || style="text-align:center;"|Sequential equivalent-time sampling: the single sample is taken for each recognized trigger after a time delay which is incremented after each cycle.
|-
|}
 
 
== Scopes ==
== Scopes ==
<div style="column-count:8;-moz-column-count:8;-webkit-column-count:8">
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* [[567]]
* [[567]]
* [[568]]
* [[568]]
* [[:Category:11800_series_mainframes|11800 Series]]
* [[:Category:TDS800_series_scopes|TDS800 Series]]
</div>
</div>


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* [[4S2|4S2A]]
* [[4S2|4S2A]]
* [[4S3]]
* [[4S3]]
* [[5S14N]]
* [[5T1]]
* [[5T1A]]
* [[5T3]]
* [[7S11]]
* [[7S11]]
* [[7S12]]
* [[7S12]]
* [[7S14]]
* [[7T11]]
* [[7T11]]
* [[7T11A]]
* [[7T11A]]
</div>
</div>
* [[7000 and 3S series sampling heads]]
* [[:Category:11800 series sampling plugins|11800 series sampling plugins]]


== Reading ==
== Reading ==
* [http://w140.com/tek_sampling_notes.pdf Sampling Notes, Tektronix]
* [http://w140.com/tek_sampling_notes.pdf Sampling Notes, Tektronix]
* [http://w140.com/kurt/50_years_sampling.pdf 50 Years of RF and Microwave Sampling, Mark Kahrs]
* [http://www.kahrs.us/~mark/pdf/papers/MTT2003.pdf 50 Years of RF and Microwave Sampling, Mark Kahrs (2003)]
* [http://w140.com/tek_concepts_sampling.pdf Sampling Oscilloscope Circuits, John Mulvey, Tektronix]
* [http://w140.com/tek_concepts_sampling.pdf Sampling Oscilloscope Circuits, John Mulvey, Tektronix]
* [http://w140.com/tek_s-series_sampling_heads.pdf Tektronix S-series Sampling Heads (PDF)]
* [https://kh6htv.files.wordpress.com/2015/11/an-02a-oscopes.pdf James R. Andrews, ''Comparison of Ultra-Fast Rise Sampling Oscilloscopes'', Picosecond Pulse Labs Application Note 2a, 1989 (PDF)]
* [http://w140.com/mtt_2003_PSPL.pdf PSPL MTT 2003 paper: 100 GHz Sampler (PDF)]
* [http://w140.com/andrews_construction_of_broadband_sampling_head.pdf Construction of a Broadband Universal Sampling Head, J. R. Andrews and G. DeWitte]
* [http://w140.com/tek_sampling_instruments_brochure.pdf Tektronix Sampling Instruments Brochure (PDF)]
* [[Media:Cliff moulton sensitive sampling plug-ins no ocr.pdf|Sensitive Sampling Plug-ins Add New Capabilities, Cliff Moulton (PDF, needs OCR)]]
* [[Media:Sampling-Concepts ServiceScope Feb1965.pdf|February 1965 Service Scope: Sampling Concepts Reviewed]]
* [[Media:Cern 61-15 nanosecond sampling oscilloscope.pdf]]
* [[Media:Tektronix Type N Movie Notes.pdf|Transcript of "Sampling Oscilloscopes and Techniques" Training Film by Norm Winningstad (PDF)]]
* [[Media:062-5260-00.pdf|Introduction to Sampling Concepts]] (PDF)
* [[Media:03W-8605-3.pdf | XYZs of Oscilloscopes ]] (PDF)
* [[Media:High speed measurements using sampling techniques.pdf|High-Speed Measurements Using Sampling Techniques (Student Workbook)]] (PDF)
[[Category:Sampling scopes]]

Revision as of 07:14, 7 June 2022

A sampling oscilloscope captures the time domain waveform at discrete time intervals using a sampling circuit. These captured voltages are then either stored in an analog fashion (integrator circuits and CRTs) or digitized and processed digitally. Through the 1960s, the sampling group at Tektronix was led by Al Zimmerman.

A distinction is made between real-time and equivalent time sampling. Real-time sampling requires a sampling rate of at least twice the highest signal bandwidth to capture the signal without aliasing artifacts. It is rare with analog oscilloscopes, but the method of choice for low to medium speed digital storage oscilloscopes, and allows for single shot waveform acquisition.

Equivalent time sampling requires repetitive signals but allows to capture a fast signal with a sampling rate much slower than the signal bandwidth. When talking about a "Sampling Oscilloscope" this approach is usually referred to. For digital instruments the term "Digital Sampling Oscilloscopes" is used. However the lines are blurry, since many instruments utilizing sampling concepts switch between different acquisition modes depending on the timebase setting.


Real-Time Sampling Equivalent Time Sampling


Equivalent time sampling is further divided into sequential, and random sampling. Instruments that have a random sampling mode usually also have a sequential sampling mode, e.g., the 7T11.

Random equivalent-time sampling: the sampling clock runs asynchronously with the input signal and the trigger. Sequential equivalent-time sampling: the single sample is taken for each recognized trigger after a time delay which is incremented after each cycle.


Scopes

Plug-ins

Reading