US 11,722,872 B2
Near-field communication device and method
Alexandre Tramoni, Le Beausset (FR)
Assigned to STMicroelectronics (Rousset) SAS, Rousset (FR)
Filed by STMicroelectronics (Rousset) SAS, Rousset (FR)
Filed on Sep. 17, 2021, as Appl. No. 17/478,399.
Claims priority of application No. 2009975 (FR), filed on Sep. 30, 2020.
Prior Publication US 2022/0103992 A1, Mar. 31, 2022
Int. Cl. H04W 4/80 (2018.01); H02J 50/80 (2016.01); H02J 50/10 (2016.01); H04B 5/00 (2006.01)
CPC H04W 4/80 (2018.02) [H02J 50/10 (2016.02); H02J 50/80 (2016.02); H04B 5/0025 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method, comprising:
detecting, by a first near-field communication device, the presence of a second near-field communication device;
detecting, with the first near-field communication device, whether the second near-field device is a first type of device configured to be charged by the first near-field communication device or a second type of device configured to exchange data with the first device;
if the second near field communication device is the first type of device:
adjusting, by a control device of the first near-field communication device, an impedance of an impedance matching circuit of a near-field communication circuit of the first near-field communication device from a first impedance value to a second impedance value by adjusting a capacitance of a variable capacitor; and
transmitting an electromagnetic field with an antenna of the first near-field communication device while the matching circuit is at the second impedance value;
if the second near-field communication device is the second type of device:
keeping an impedance of the impedance matching circuit unchanged; and
transmitting an electromagnetic field with the antenna while the matching circuit is at the first impedance value.