Abstract: An electronic label reading system includes an interrogator including a transmitter and a receiver. The system also has a transmitter antenna connected to the transmitter for generating an interrogation electromagnetic field through which objects possessing code responding labels may pass. The code responding labels include label receiving antennas for receiving from the interrogation field a label interrogation signal, and generate label reply signals, and, from the label reply signals, reply electromagnetic fields. The system also has a receiver antenna connected to the receiver for receiving the reply signals from the label reply fields. The interrogation field and label reply fields provide a communication channel from the labels to the interrogator, and the interrogator signals to the labels condition information indicative of the condition of the communication channel.

Abstract: An electronic label reading system is disclosed having an interrogator including a transmitter for generating an interrogation signal and a receiver for detecting and decoding a reply signal. The system also has an interrogation field creation means including a transmitter antenna connected to the transmitter for generating from the interrogation signal an interrogation electromagnetic field through which objects possessing code responding labels may pass. The code responding labels include label receiving antennas for receiving from the interrogation field a label interrogation signal, means for generating label reply signals, and means for generating from the label reply signals, reply electromagnetic fields. The system also has a receiver antenna connected to the receiver for receiving the reply signals from the label reply fields.

Abstract: An identification system having an electronic label for processing articles such as baggage or carrier cargo. The system uses the principle of electromagnetic communication in which an interrogator containing a transmitter generates an electromagnetic field through which the electronic label containing a label receiving antenna may pass. The electronic label is attached to the article being processed and includes means for sensing the electromagnetic field and means for generating intermittently repeated label reply signals. The system includes a receiver for detecting and decoding the label reply signal. The electronic label replies intermittently as long as it is within the electromagnetic field, and the field is maintained for a period of time which is greater than the time interval between the intermittently repeated label replies.

Abstract: An identification and telemetry system comprising: a signal responding label including a first antenna for receiving an interrogation signal and for scattering a reply signal, an impedance connected to the first antenna, means for generating the reply signal and means for varying the impedance connected to the first antenna in accordance with the reply signal; and an interrogator comprising a second antenna for transmitting an interrogation signal and for receiving the reply signal, a transmitter connected to the second antenna and including a generator of pulsed radio frequency energy, means for separating the reply signal from the transmitted signal, a receiver connected to the second antenna and means within the receiver for detecting and decoding the reply signal.

Abstract: An apparatus for remote temperature reading particularly for the reading of the temperature of an article or animal at a distance by means of an electromagnetically interrogatable label attached to or implanted in the article or animal the label being constructed to be capable of receiving an electromagnetic signal from a transmitter, converting the signal to a surface acoustic wave, passing the wave over a path on the label, reconverting the surface acoustic wave to an electromagnetic signal and retransmitting it to a receiver. The path of the surface acoustic wave is of a material such that the time of travel of the surface acoustic wave over the path is a function of the temperature of the path and thus of the label. The receiver is constructed to measure the time interval between electromagnetic signals produced by the passage of the surface acoustic wave past a transducer or transducers in the path and thereby provide an output indicative of the temperature of the environment of the label.

Abstract: A system for the remote identification of objects using near-field electromagnetic coupling between an interrogator a transponder and a receiver in which a reply carrier at a subharmonic of the interrogation frequency is obtained by regulating, with minimum energy loss and synchronously with the interrogator signal, the energy exchange process between the transponder coupling element and a complementary storage element, and further varying, also with minimum energy loss and synchronously with the resultant oscillation waveform, the said energy exchange process so that the reply carrier becomes modulated with an information bearing code, the modulation rate being not constrained by the transponder tuned circuit bandwidth.

Abstract: The invention provides a gyroscope employing a sensitive element rotated by a hysteresis motor and which has an improved bias repeatability, the bias arising from vibration of the sensitive element imparted thereto by the hysteresis motor. An identifiable point associated with the sensitive element (9) is sensed by first sensor means (37, 38, 67, 71) and a pole vector associated with the hysteresis motor (6) is sensed directly or indirectly by second sensor means (64), the outputs of these sensor means being applied to comparator means (73) which is operable to compare the phase of the pole vector (V.sub.p) with respect to the identifiable point. Control means (76, 79) are also provided which are responsive to the output of the comparator means (73) and operable to adjust the phase of the pole vector (V.sub.p) with respect to the identifiable point to a required relationship, the gyroscope further comprising means (73), for maintaining that required relationship once established.