The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 28, 2025
Filed:
Dec. 22, 2020
Applicant:
Stmicroelectronics (China) Investment Co., Ltd., Shanghai, CN;
Inventors:
Tianhao Xiong, Shanghai, CN;
Gang Wu, Shanghai, CN;
Assignee:
STMICROELECTRONICS (CHINA) INVESTMENT CO., LTD., Shanghai, CN;
Primary Examiner:
Int. Cl.
CPC ...
H04B 5/79 (2024.01); H04B 5/26 (2024.01); H04B 5/45 (2024.01); H04B 5/77 (2024.01);
U.S. Cl.
CPC ...
H04B 5/79 (2024.01); H04B 5/26 (2024.01); H04B 5/45 (2024.01); H04B 5/77 (2024.01);
Abstract
A near field communication (NFC) reader detects whether NFC devices are passive NFC devices or active NFC devices. The NFC reader outputs an interrogation signal and a carrier signal. When the NFC reader receives a response signal from an NFC device responsive to the interrogation signal, the NFC reader adjusts the frequency of the carrier signal before the end of the response signal. The NFC reader determines whether the NFC device is a passive NFC device or an active NFC device based on characteristics of the remaining portion of the response signal.