Synchronization method of an active load modulation clock within a transponder
US10122557B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 30, 2018 |
| Grant date | Nov 6, 2018 |
| Priority date | — |
| Expiry date | Apr 30, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/361
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method of wireless communication includes transmitting frames from a transponder to a reader and synchronizing between a reader carrier frequency and an active load modulation (ALM) carrier frequency within each transmitted frame. Each transmitted frame includes ALM carrier bursts generated from subcarrier modulation by binary phase shift keying (BPSK) data encoding and producing signal oscillations at a transponder antenna after each ALM carrier burst generation, The synchronizing occurs at each phase change of the data encoding when no burst is generated during a half period of the subcarrier preceding the phase change and a half period of the subcarrier following this phase change. The transponder antenna has a moderate quality factor sufficient to naturally damp the signal oscillations so that the synchronizing is performed without performing any controlled signal oscillations damping.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.