US 12,332,299 B2
Removing test equipment noise from power spectral density measurements
Chen Cao, Shanghai (CN); Christian Volf Olgaard, Saratoga, CA (US); Ruizu Wang, Santa Clara, CA (US); and Qingjie Lu, Shanghai (CN)
Assigned to LitePoint Corporation, San Jose, CA (US)
Filed by LitePoint Corporation, San Jose, CA (US)
Filed on May 5, 2023, as Appl. No. 18/144,019.
Claims priority of application No. 202310461854.9 (CN), filed on Apr. 26, 2023.
Prior Publication US 2024/0361376 A1, Oct. 31, 2024
Int. Cl. G01R 31/28 (2006.01); G01R 23/18 (2006.01)
CPC G01R 31/2837 (2013.01) [G01R 23/18 (2013.01); G01R 31/2841 (2013.01)] 23 Claims
OG exemplary drawing
 
1. A method comprising the following operations:
(i) receiving a device signal from a device under test (DUT);
(ii) setting an attenuation value;
(iii) applying the attenuation value to the device signal to produce an attenuated device signal for a frequency spectrum analyzing device, the frequency spectrum analyzing device producing a noise signal;
(iv) obtaining a power spectral density value using the frequency spectrum analyzing device, where a power spectral density comprises a power, at a frequency value, of a combined signal that is based on the attenuated device signal and the noise signal;
(v) repeating operations (ii), (iii), and (iv) one or more times to produce multiple power spectral density values;
(vi) repeating operations (i), (ii), (iii), (iv), and (v) one or more times to add power spectral density values to the multiple power spectral density values; and
(vii) obtaining a power spectral density of the device signal by removing at least some of the noise signal from the combined signal by performing an optimization process that disassembles the combined signal into the power spectral density of the device signal and a power spectral density of the noise signal, the optimization process being based on the multiple power spectral density values.