Subset selection of RFID tags using light
US8395505B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 7, 2009 |
| Grant date | Mar 12, 2013 |
| Priority date | — |
| Expiry date | Aug 29, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M7/217
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Methods and apparatuses for selecting a subset of RFID tags are provided in some embodiments. These methods and apparatuses utilize the susceptibility to light by persistent nodes found in passive tags. Light can be used to intentionally reduce persistence times in a particular subset tags or even an individual tag. Then, persistent nodes can be used as a selection criterion to distinguish previously illuminated tags from non-illuminated tags. In other embodiments, a power circuit receives a RF input source and generates a direct current (DC) output voltage. The circuit includes a bias circuit to supply a gate to source bias, which is independent of the DC output voltage. The circuit further includes a voltage multiplier circuit that is coupled to the bias circuit. The voltage multiplier circuit has MOS transistors with one transistor to receive the gate to source bias.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.