Reflective vector modulators
US9537468B2 · kind B2 · utility
Inventor
Key dates
| Filing date | Dec 17, 2015 |
| Grant date | Jan 3, 2017 |
| Priority date | — |
| Expiry date | Dec 17, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H7/383
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Technologies for RFID positioning and tracking apparatus and methods are disclosed herein. The apparatus and methods disclose a radio-frequency identification positioning system that includes a radio-frequency identification reader and a phased-array antenna coupled to the radio-frequency identification reader. Techniques are applied to reduce in-reader and in-antenna signal leakages. Techniques are applied to position and track RFID tags. Circuits with leakage cancellation abilities are also disclosed. Reflective vector attenuators with tunable impedance load are also disclosed. Polarization adjustable antennas with matching circuits used in the RFID positioning system are also disclosed. Circuits to re-transmit a received signal at a higher amplitude to enhance radio link range are also disclosed. Techniques are applied to increase the level of scattered radio signals from RFID tags.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.