Real-equivalent-time oscilloscope
AssigneeTektronix, Inc.
InventorKan Tan
Life of this patent
Estimating the term…
Abstract
A test and measurement instrument, such as an oscilloscope, having a Nyquist frequency lower than an analog bandwidth, the test and measurement instrument having an input configured to receive a signal under test having a repeating pattern, a single analog-to-digital converter configured to receive the signal under test and sample the signal under test over a plurality of repeating patterns at a sample rate, and one or more processors configured to determine a frequency of the signal under test and reconstruct the signal under test based on the determined frequency of the signal, the pattern length of the signal under test, and/or the sample rate without a trigger.
Claims20
An oscilloscope having a Nyquist frequency lower than an analog bandwidth, the oscilloscope comprising:
- an input configured to receive a signal under test having a repeating pattern;
- a single analog-to-digital converter configured to receive the signal under test and sample the signal under test over a plurality of repeating patterns at a sample rate;
- and
- one or more processors configured to determine a frequency of the signal under test and reconstruct the signal under test based on the determined frequency of the signal under test and the sample rate without a trigger.
A method for reconstructing a signal under test in an oscilloscope having a Nyquist frequency lower than an analog bandwidth, comprising:
- receiving the signal under test having a repeating pattern;
- sampling at a sample rate the signal under test over a plurality of repeating patterns to digitize the signal using a single analog-to-digital converter;
- determining a frequency of the sampled signal under test;
- and
- reconstructing the signal under test based on the determined frequency and the sampling rate without utilizing a trigger.
A method for reconstructing a signal under test in an oscilloscope, comprising:
- sampling a signal under test;
- determining a nominal unit interval value based on the signal under test;
- obtaining a first window of samples, including estimating unit interval values around the nominal unit interval value to determine an averaged first unit interval value having a first period value;
- obtaining a second window of samples, including estimating unit interval values around the averaged first unit interval to determine an averaged second unit interval value with a search range of unit intervals for the second window of samples narrower than a search range of the unit interval for the first window of samples;
- normalizing a sampling time based on the first window of samples and the second window of samples;
- and
- reconstructing the signal under test based on the normalized sampling time.
Dependencies are inferred from the claim text.