Antenna matching circuit
AssigneeBattelle Memorial Institute K1-53
InventorCurtis Lee Carrender
Life of this patent
Estimating the term…
Abstract
A matching circuit for use with radio frequency identification tag antennas configured for modulated backscatter, the circuit including a stub circuit coupled to a detector diode and an antenna and sized and shaped to match a predetermined frequency. The stub circuit is also designed to couple to the antenna such that a resulting phase is seen at the output, preferably 180° from that seen at the input. In addition, the stub circuit is structured to perform as an antenna, thus increasing the sensitivity of the overall circuit and maximizing efficiency and performance.
Claims31
A diode matching antenna circuit, comprising:
- a diode detector circuit having a first terminal coupled to an antenna and a second terminal;
- and
- a stub circuit coupled to the second terminal of the diode detector circuit, the stub circuit structured to match the impedance of the diode detector circuit in combination with the antenna to maximize the performance of the diode detector circuit.
A radio frequency identification tag, comprising:
- a circuit for processing radio frequency identification signals;
- and
- an antenna circuit coupled to the processing circuit and configured for modulated backscatter, the antenna circuit comprising:
- a detector circuit having a first terminal coupled to an antenna and a second terminal;
- and
- a stub circuit coupled to the second terminal of the detector circuit, the stub circuit structured to match the impedance of the detector circuit in combination with the antenna to maximize the performance of the detector circuit.
A radio frequency identification tag system, comprising:
- a transceiver configured to transmit an receive radio frequency signals;
- and
- at least one radio frequency identification tag, comprising:
- a circuit for processing radio frequency identification signals;
- and
- and antenna circuit coupled to the processing circuit and configured for modulated backscatter, the antenna circuit comprising:
- a diode detector circuit having a first terminal coupled to an antenna and a second terminal;
- and
- a stub circuit coupled to the second terminal of the diode detector circuit, the stub circuit structured to match the impedance of the diode detector circuit in combination with the antenna to maximize the performance of the diode detector circuit.
A modulated backscatter antenna circuit for a radio frequency identification tag, the circuit comprising:
- means for detecting the radio frequency identification signals, the detecting means comprising an antenna means and a diode means coupled together;
- and
- a stub circuit means for matching the impedance of the diode means in combination with the antenna means to maximize the performance of the diode means.
A radio frequency identification tag circuit, comprising:
- means for processing radio frequency signals;
- and
- radio frequency signal detection means coupled to the processing means and configured for modulated backscatter, the detection means comprising:
- means for detecting the radio frequency identification signals, the detecting means comprising an antenna means and a diode means coupled together;
- and
- a stub circuit means for matching the impedance of the diode means in combination with the antenna means to maximize the performance of the diode means.
Dependencies are inferred from the claim text.