Sampling oscilloscope: Difference between revisions

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Tektronix made oscilloscopes and plug-ins intended for [[Sampler|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 was led by [[Al Zimmerman]].
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 [[wikipedia: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.  


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 artifacts. It is rare with analog oscilloscopes, but the method of choice for low to medium speed digital oscilloscopes, and allows for single shot waveform aquisition.


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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. However the lines a blurry, since many instruments utilizing sampling concepts switch between different acquisition modes depending on the timebase setting.


Equivalent time sampling is further divided into sequential, and [[random sampling]].
Equivalent time sampling is further divided into sequential, and [[random sampling]].
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| [[File:RandomTimeSampling_Fig33_XYZs_of_Oscill.png|600px]] || [[File:SequentialTimeSampling_Fig34_XYZs_of_Oscill.png|600px]]
| [[File:RandomTimeSampling_Fig33_XYZs_of_Oscill.png|600px]] || [[File:SequentialTimeSampling_Fig34_XYZs_of_Oscill.png|600px]]
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| style="text-align:center;"|In random equivalent-time sampling, the sampling clock runs asynchronously with the input signal and the trigger.      || style="text-align:center;"|In sequential equivalent-time sampling, the single sample is taken for each recognized trigger after a time delay which is incremented after each cycle.
| 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.
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== Scopes ==
== Scopes ==
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* [[567]]
* [[567]]
* [[568]]
* [[568]]
* [[11801]]
* [[:Category:11800_series_mainframes|11800 Series]]
* [[TDS820]]
* [[:Category:TDS800_series_scopes|TDS800 Series]]
* [[TDS840]]


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== Reading ==
== Reading ==
* [http://w140.com/tek_sampling_notes.pdf Sampling Notes, Tektronix]
* [[Media:85W-23777-0.pdf|Sampling Notes]], Tektronix
* [[Media:062-1172-00.pdf|Sampling Oscilloscope Circuits]], John Mulvey, Tektronix
* [[Media:MTT_2003_PSPL.pdf|PSPL MTT 2003 paper: 100 GHz Sampler]]
* [https://www.semanticscholar.org/paper/Construction-of-a-Broadband-Universal-Sampling-Head-Andrews-DeWitte/d6259cb3e98c0388d61d230f2413485fde50b8d0 Construction of a Broadband Universal Sampling Head, J. R. Andrews and G. DeWitte]
* [[Media:Tek_sampling_instruments_brochure.pdf|Tektronix Sampling Instruments Brochure]]
* [http://www.kahrs.us/~mark/pdf/papers/MTT2003.pdf 50 Years of RF and Microwave Sampling, Mark Kahrs (2003)]
* [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]
* [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]
* [http://w140.com/tek_s-series_sampling_heads.pdf Tektronix S-series Sampling Heads (PDF)]
* [[Media:Cliff moulton sensitive sampling plug-ins.pdf|Sensitive Sampling Plug-ins Add New Capabilities, Cliff Moulton (OCR)]]
* [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:Sampling-Concepts ServiceScope Feb1965.pdf|February 1965 Service Scope: Sampling Concepts Reviewed]]
* [[Media:Cern 61-15 nanosecond sampling oscilloscope.pdf]]
* [[Media:Cern 61-15 nanosecond sampling oscilloscope.pdf]]

Latest revision as of 19:06, 9 March 2024

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

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