Loop antenna compensator
First Claim
1. A compensator antenna tuning circuit for generating a magnetic field at a carrier frequency from a transceiver for coupling energy to a tag loop antenna and for reading signals from the tag loop antenna, comprisingan outer antenna loop lying in an antenna plane, an inner compensating loop lying in the antenna plane, a tuning circuit connected within the inner compensating loop, the tuning circuit and the inner compensating loop providing a double maxima frequency response having a first maxima at the carrier frequency and a second maxima at a low sideband frequency for more efficient transmitting and receiving of energy from the tag loop antenna at the carrier frequency and at the low sideband frequency.
1 Assignment
0 Petitions
Accused Products
Abstract
Compensating electrical circuits are incorporated into loop antenna configurations for improved energy efficiency and extension of the magnetic fields for improved magnetic field coupling and reading of the tag by a reader. The tuning and compensating circuits provide a reader magnetic response having maxima at the center carrier frequency and at the low sideband frequency for improved reception of return signals from the tag to the reader.
32 Citations
7 Claims
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1. A compensator antenna tuning circuit for generating a magnetic field at a carrier frequency from a transceiver for coupling energy to a tag loop antenna and for reading signals from the tag loop antenna, comprising
an outer antenna loop lying in an antenna plane, an inner compensating loop lying in the antenna plane, a tuning circuit connected within the inner compensating loop, the tuning circuit and the inner compensating loop providing a double maxima frequency response having a first maxima at the carrier frequency and a second maxima at a low sideband frequency for more efficient transmitting and receiving of energy from the tag loop antenna at the carrier frequency and at the low sideband frequency.
Specification