Abstract: A resonant circuit tuning system and a method for tuning are provided. The resonant circuit tuning system may include an LCR circuit and a reactive element magnetically coupled to the LCR circuit.

Abstract: A resonant circuit tuning system and a method for tuning are provided. The resonant circuit tuning system may include a resonant circuit having a first capacitive element in series between a transmitter and an antenna coil and a second capacitive element in parallel with the transmitter and the antenna coil. At least one of the first capacitive element and second capacitive element may be configured to be varied. The resonant circuit tuning system also may include a controller for controlling a variable value of at least one of the first and second capacitive elements.

Abstract: A deactivator having a deactivation antenna coil and a capacitor to store energy. The deactivator converts the stored energy to an alternating current over a deactivation period to generate a deactivation magnetic field when driven through the deactivation antenna coil during the deactivation period. The alternating current defines a ring down envelope during the deactivation period. An energy recovery module having an electrical impedance is coupled to the deactivator to recover a portion of the energy converted to the alternating current during a portion of the deactivation period based on the impedance. Other embodiments are described and claimed.

Abstract: A magnetic core antenna system including a magnetic core and a winding network. The winding network may be configured with a non-uniform ampere-turn distribution to achieve a desired flux density in the core. The network may include a plurality of windings configured to provide a winding impedance facilitating optimal transmitter power delivery to the windings. A magnetic core may be constructed from multiple components having longitudinal contact surfaces and joined by a transverse clamping force. An air gap may be provided between the components to allow relative movement therebetween.

Abstract: A method and apparatus to perform resonant recharge transfers energy from an AC power source (e.g., a power line) or from a DC power source or from bulk capacitors to a deactivation capacitor. The resonant recharge occurs faster than conventional techniques without the need for dissipative current limiting control elements. Through the employment of a resonant approach, the natural impedance of the resonant circuit limits the current without high resistive losses of a limiting resistor or other current limiting regulator. This may increase the efficiency of the recharge circuit and may charge the deactivation capacitor to a voltage that is higher than the voltage of the power source.

Abstract: An EAS or RFID system including first and second core antenna systems. The first and second antenna systems establish magnetic fields having opposite directions and are positioned so that the fields at least partially cancel outside of an interrogation zone for detecting an EAS or RFID tag. There is also provided an EAS or RFID wherein the magnetic field direction established by a core antenna is varied at certain time intervals to minimize the effects of null zones in the interrogation zone.

Abstract: An EAS or RFID system including first and second core antenna systems. The first and second antenna systems establish magnetic fields having opposite directions and are positioned so that the fields at least partially cancel outside of an interrogation zone for detecting an EAS or RFID tag. There is also provided an EAS or RFID wherein the magnetic field direction established by a core antenna is varied at certain time intervals to minimize the effects of null zones in the interrogation zone.

Abstract: A magnetic core antenna system including a magnetic core and a winding network. The winding network may be configured with a non-uniform ampere-turn distribution to achieve a desired flux density in the core. The network may include a plurality of windings configured to provide a winding impedance facilitating optimal transmitter power delivery to the windings. A magnetic core may be constructed from multiple components having longitudinal contact surfaces and joined by a transverse clamping force. An air gap may be provided between the components to allow relative movement therebetween.

Abstract: An electronic article surveillance (EAS) antenna system including at least one transmit antenna and at least one amorphous core receiver antenna adapted for installation on the floor, in the grout region of the floor, or under the flooring of a passageway. An EAS system including at least one perimeter loop antenna adapted to extend around the entire perimeter of a passageway is also provided. The system may further include at least one floor antenna adapted for installation within a region of a floor of a passageway and at least one ceiling antenna adapted for installation adjacent a ceiling of the passageway.

Abstract: A magnetic core transceiver antenna for EAS marker detection is provided. The core includes a stack of amorphous alloy ribbons insulated from each other and laminated together. A coil winding of wire, also insulted from the ribbons, and connected to an electronic controller provides the transmitter and receiver modes. The transceiver antenna is optimized for the dual mode operation, and is smaller and uses less power than conventional air-core EAS antennas with equivalent performance. Complex core geometries, such as a sandwiched stack of different sized ribbons, can be implemented to vary the effective permeability of the core to customize antenna performance. Multiple transceiver antennas can be combined to increase the size of the generated EAS interrogation zone.