公开(公告)号：US20250138074A1

公开(公告)日：2025-05-01

申请号：US18813123

申请日：2024-08-23

Applicant: Keysight Technologies, Inc.

Inventor： David Leyba

IPC: G01R29/26 ,  G01R13/02

Abstract: A test system implemented method is for measuring the noise margin of a repeating signal under test (SUT). The method includes determining a digitizer noise of a digitizer channel of the test system, and applying the repeating SUT to the digitizer channel of the test system. An oversampled equivalent-time waveform representation of the repeating SUT is acquired, and then a filtered waveform representation is obtained. A noise margin om of the repeating SUT is determine in accordance with the equation σm=(σc2+σi2−σd2)1/2, where σc is a standard deviation of a maximum amount of gaussian noise that can added to the filtered waveform representation without its symbol error rate (SER) exceeding a target value, σi is a standard deviation of the digitizer noise, and σd is a standard deviation of the noise components removed to obtain the filter waveform representation.

公开(公告)号：US20250138073A1

公开(公告)日：2025-05-01

申请号：US18383921

申请日：2023-10-26

Applicant: Keysight Technologies, Inc.

Inventor： Marlin E. Viss ,  David Leyba

IPC: G01R29/26 ,  G01R13/02

Abstract: A test system implemented method removes intrinsic noise from a waveform representation of a repeating signal under test (SUT). The method includes obtaining an oversampled equivalent-time waveform representation of the repeating SUT. The method further includes obtaining a time-domain representation of a combined noise of the equivalent-time waveform above the deterministic maximum frequency by applying the equivalent-time waveform to a high-pass filter. The method further includes determining a standard deviation of the time-domain representation of the combined noise, and determining a correction factor α in accordance with the standard deviation of the digitizer noise, and the standard deviation of the time-domain representation of the combined noise. The method further includes applying the equivalent-time waveform representation to a low-pass filter having a unity magnitude response at frequencies below the cutoff frequency and a correction factor magnitude response at frequencies above the cutoff frequency.