US 12,442,837 B2
Real-equivalent-time clock recovery for a nearly-real-time real-equivalent-time oscilloscope
Kan Tan, Portland, OR (US)
Assigned to Tektronix, Inc., Beaverton, OR (US)
Filed by Tektronix, Inc., Beaverton, OR (US)
Filed on Aug. 24, 2022, as Appl. No. 17/894,927.
Claims priority of provisional application 63/237,503, filed on Aug. 26, 2021.
Prior Publication US 2023/0070298 A1, Mar. 9, 2023
Int. Cl. G01R 13/02 (2006.01); G01R 23/02 (2006.01)
CPC G01R 13/029 (2013.01) [G01R 13/0218 (2013.01); G01R 23/02 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A test and measurement device, comprising:
an input port configured to receive a signal from a device under test, the signal having a symbol rate;
one or more analog-to-digital converters to convert the signal to waveform samples at a sampling rate; and
one or more processors configured to execute code that, when aliasing is present, causes the one or more processors to:
determining that aliasing is present when a Nyquist frequency of the sampling rate is less than or equal to a bandwidth of the device and that the sampling rate is greater than the symbol rate;
up-sample a portion of the signal between the Nyquist frequency and the bandwidth having aliased samples to produce up-sampled samples using a sample rate that supports real-time sampling;
use the up-sampled samples to produce a real-time waveform;
perform clock recovery on the real-time waveform to produce a recovered clock; and
resample the aliased samples using the recovered clock to produce a non-aliased waveform.