Abstract: The universal electronic identification tag is for use with a variety of readers of different designs including a control reader which can be used to control the operations of the universal tag. A reader interrogates a tag by transmitting a carrier. The universal tag comprises a transducer, a modulator connected across the transducer, and a control means. The control means causes the modulator to drive the transducer with a plurality of different message waveforms after interrogation by a reader, the tag identity being embedded in each of the message waveforms. The message waveforms can be transmitted either simultaneously, sequentially, or both ways. A message waveform is comprised of a sequence of contiguous waveform segments, each waveform segment representing the value of an N-bit group, N being an integer. A waveform segment is a periodic signal characterized by the parameters frequency, phase, and amplitude.

Abstract: The electronic identification system provides two-way communications between reader and tags using alternating magnetic fields established by the reader and tag. Communication is accomplished by utilizing either a one-step or a two-step modulation process in which the information to be communicated either modulates an alternating magnetic field directly or modulates a periodic signal which modulates an alternating magnetic field. The coil in the reader that is used to establish an alternating magnetic field is transformer-coupled through capacitors to a push-pull driving circuit consisting of four field-effect transistors connected in a bridge arrangement. The coil, capacitors, and coupling circuitry are maintained in a tuned condition by continually adjusting either the driving frequency, the coil inductance, or the capacitor capacitance during communications.

Abstract: The coil in the reader that is used to establish an alternating magnetic field is transformer-coupled through capacitors to a push-pull driving circuit consisting of four field-effect transistors connected in a bridge arrangement. The coil, capacitors, and coupling circuitry are maintained in a tuned condition by continually adjusting either the driving frequency, the coil inductance, or the capacitor capacitance during communications. A tag utilizes a coil to couple with the reader's alternating magnetic field and a capacitor to resonate the coil, thereby extracting power from the field more efficiently. Transformer coupling of the coil and capacitor is utilized for improved impedance matching. The coil, capacitor, and coupling circuitry can be maintained in a tuned condition by continually adjusting either the coil inductance, or the capacitor capacitance during communications. Certain configurations of the system may require that tuning maintenance be discontinued during the transmission of data.

Abstract: An extended-range reader for use in identifying the tag of an object. The reader includes a winding of conducting wire for generating an interrogating magnetic field. The winding may be either a coil assembly consisting of a plurality of coils spaced at intervals along a common axis or a solenoid. The winding is limited to those having values of D/L less than four where D is the smallest transverse dimension of the winding and L is the length. The winding is adapted to receive a structure within the winding for providing objects a passageway through the winding. The axis of the winding may be either straight or curved. To improve the magnetic field generating capability of the winding, a magnetic shunt encircling the winding can be added. Also included is a structure within the winding for providing objects a passageway through the winding, the structure having openings for object ingress and egress.

Abstract: The universal electronic identification tag is for use with a variety of readers of different designs including a control reader which can be used to control the operations of the universal tag. A reader interrogates a tag by transmitting a carrier. The universal tag comprises a transducer, a modulator connected across the transducer, and a control means. The control means causes the modulator to drive the transducer with a plurality of different message waveforms after interrogation by a reader, the tag identity being embedded in each of the message waveforms. The message waveforms can be transmitted either simultaneously, sequentially, or both ways. A message waveform is comprised of a sequence of contiguous waveform segments, each waveform segment representing the value of an N-bit group, N being an integer. A waveform segment is a periodic signal characterized by the parameters frequency, phase, and amplitude.

Abstract: A field coil signal transmission and tag reading circuit is disclosed for use in an inductive tag reader system. The circuit is coupled to an oscillator which provides a drive signal to a differential driver. The driver transforms the clock signal into first and second complementary drive signals. The drive signals are coupled to a field coil through a plurality of capacitors for inductively producing an output power signal. The capacitors are differentially coupled to the coil, so that each input of the coil is coupled to one of the clock signals through a separate capacitor. A bridge rectifier is coupled to the field coil opposite the capacitors for producing an output comprising a direct current element and an alternating current element superimposed on the DC element. A resistance-capacitance (R-C) filter, coupled to the bridge rectifier, provides a filtered rectifier output signal. The output signal can be decoded downstream of the R-C filter using several different decoding schemes known in the art.

Abstract: The hypodermic syringe for implanting objects in the bodies of birds, fish, animals, and humans consists of a barrel, a canula attached to one end of the barrel, and a plunger that can be moved back and forth within the barrel. A user implants an object by placing the object inside the canula, making an incision with the canula, and then pushing on the plunger thereby causing the object to move from the canula through the incision and into the body. The canula is designed to securely hold an implant object in a fixed position within the canula from the moment of insertion into the canula until the moment of implantation. The canula is also provided with a window that permits a user to observe the presence of an object and, in the case of objects that are electronic identification tags, to read the data stored in a tag with electromagnetic readers. The plunger is intended to provide the user with the same "feel" as a conventional fluid-injection-type hypodermic syringe.

Abstract: A container providing selective access to stored objects consists of a plurality of cells for storing objects and a mechanism for causing the cells to open and close in accordance with a control pattern that specifies the cells that are to be opened and the cells that are to be closed. A user, by selecting an appropriate control pattern gains access to those cells in which he has an immediate interest. The user may quickly gain access to other combinations of cells simply by selecting other control patterns.

Abstract: A field coil signal transmission and tag power consumption measurement circuit for use in an inductive tag reader system. The circuit is coupled to an oscillator which provides a drive signal to a differential driver. The driver transforms the clock signal into first and second complementary drive signals. The drive signals are coupled to a field coil through a plurality of capacitors for inductively producing an output power signal. The capacitors are differentially coupled to the coil, so that each input of the coil is coupled to one of the clock signals through a separate capacitor. A bridge rectifier is coupled to the field coil opposite the capacitors for producing an output comprising a direct current (DC) element and an alternating current (AC) element superimposed on the DC element. A resistance-capacitance (R-C) filter, coupled to the bridge rectifier, provides a filtered rectifier output signal.