Abstract: A portable communication device uses a first electrostatic antenna element and a second electrostatic antenna element and circuitry which is coupled to the first antenna element and to the second antenna element and which derives operating power from an electrostatic field in the vicinity of the first and second antenna elements. The electrostatic field may be provided by an array of exciter elements containing both horizontal and vertical exciter elements so that at some point as a communication device is moved across the exciter antenna array, the device will have sufficient power coupled to it to power up and become operational.

Abstract: An RF tagging system includes an RF tag (10, 30) and an RF tag reader 80. The RF tag includes a plurality of RF resonant circuits. Each RF resonant circuit is resonant at a given RF frequency. A group of decoder RF resonant circuits (12, 32) have resonant frequencies defining one of a plurality of predetermined decoding modalities. A group of data RF resonant circuits (14, 34) have resonant frequencies corresponding to a predetermined identification code when the resonant frequencies of the data RF resonant circuits are decoded in accordance with the one decoding modality. The RF tag reader detects the resonant frequencies of the decoder RF resonant circuits and determines the one decoding modality.

Abstract: An RF tag (10) includes a plurality of RF resonant circuits (14, 18, 22) which are disposed in a three-dimensional array within a body (30) of solid material. Selected ones of the RF resonant circuits are coated with a conductive ink (36) for programming the RF tag. Non-planar RF resonant circuits (40, 50) provide enhanced directivity. The RF resonant circuits (14, 40, 50) are disposed within an elongated body (72, 82, 94) in spaced apart and substantially axially aligned relation to provide elongated RF tag configurations. An RF tag assembly (110) includes attachment mechanisms (116, 118) for attaching an RF tag (128) to a carrier. A dual mode RF tag assembly (140) is also provided which includes a passive RF circuit (144) and an active RF circuit (142).

Abstract: An RF tag (20) includes a low profile battery power source (22). The RF tag includes an electrically insulating substrate 21, an RF transmitter (24) on the substrate for transmitting a predetermined identification code, and the battery (22). The battery includes a first pattern of conductive material to form a planar anode structure (48) and a second pattern of conductive material on the substrate to form a cathode structure (50). A protective layer (92) overlies the substrate. The protective layer includes an opening (94) to expose the anode and cathode of the battery to permit an electrolyte to be applied to the anode and cathode for completing the formation of the battery and to provide electrical energy to the RF transmitter. A manufacturing apparatus (60) is also described which permits the RF tags to be manufactured in a low cost, reel-to-reel, basis. Also described is a dispenser (100) for activating and dispensing the RF tags one at a time at a point of use.

Abstract: A tagging system (20) compensates for both resonant frequency spatial dependent shifts and resonant frequency dependent shifts for detecting data resonant circuits (DC1-DC6) on an RF tag 10 which is carried by a tagged object (34). The system includes at least one transmitter (26) and at least one receiver (28) for determining the actual resonant frequencies of reference resonant circuits (SC1-SC5, FC1-FC4) on the tag 10. A microprocessor controller (22), in response to the frequency difference between the undisturbed resonant frequencies of the reference resonant circuits and the actual resonant frequencies of the reference resonant circuits, provides compensating factors to compensate for the spatial and frequency effects of the resonant frequencies of the resonant circuits on the tag (10). The transmitter and receiver determine the actual resonant frequency of each data resonant circuit (DC1-DC6) on the tag (10).

Abstract: An RF tag (10) includes an RF receiver (16) and an RF transmitter (18). A power source (12) provides power to the receiver and transmitter. The power source includes a plurality of energy converters (22, 24, 26, 28, 30, and 32). Each energy converter is responsive to a predetermined form of incident energy for converting its respective predetermined form of incident energy to electrical current. At least two of the energy converters are responsive to respective different predetermined forms of incident energy for providing electrical current. A storage capacitor (54) stores the electrical current provided by the energy converters and is coupled to the RF receiver and RF transmitter. A plurality of RF tags (10, 110, 140, 160) utilizing the power source 12 are also described.

Abstract: An RF tagging system which provides a large number of potential identification codes without increasing the physical size of RF tags used therein includes a plurality of RF tags (20, 90, 140, 230, 250) and an external reader (200). Each RF tag includes at least one resonant circuit (22, 92, 142, 231, 251) which is resonant at any one of a plurality of different frequencies, a receiver (34, 102, 152,244, 264) for receiving an interrogation signal, and a control (36,104,154,246, 266) responsive to receipt of an interrogation signal for causing its at least one resonant circuit to be resonant at selected ones of the different frequencies in a predetermined time sequence corresponding to a predetermined identification code. The external reader includes a detector (216, 218, 220, 222) for detecting the selected resonant frequencies of the RF tags and a decoder (226) for decoding the time sequence of the selected resonant frequencies for recovering the predetermined identification code.

Abstract: RF tagging system (10) has a plurality of resonant circuits (13) on a tag (12). When the tag (12) enters a detection zone (14), the system determines the resonant frequency of each of the resonant circuits (13) and produces a corresponding code. Preferably, resonant frequency detection is implemented by simultaneously radiating signals at each possible resonant frequencies for the tag circuits (13). The system is useful for coding any articles such as baggage or production inventory. Preferably, the radiated signals are phase shifted during the detection process, and signals received by receiver antennas, besides transmitter signals, may be monitored to improve the reliability of detecting the resonant circuits (13). Also, a preferred step adjustment configuration for capacitive metalizations (106, 110) of the resonant circuits is described.

Abstract: An electronic direction finder (10) includes a navigation receiver (28) and a compass (32) to generate a bearing signal that indicates that direction of a desired destination. The bearing signal is received by a display driver (34) which causes an electronic display (14) to generate a visible image of a rotatable pointer that points in the direction of the user's desired destination. Preferably, the display also shows an electronic compass card indicating the direction of north.

Abstract: An electronic direction finder (10), having a housing (11) with a major axis (18), has a GPS receiver (28) and directional (31) and omnidirectional (30) antennas and provides an electrical signal (angle A) indicative of the direction of the housing axis (18) with respect to a predetermined compass heading (North). The electrical signal (angle A) is provided by using determined positions of the GPS receiver (28) and one GPS satellite to calculate a compass bearing from the receiver (28) to the one satellite and using the directional antenna (31) to determine the orientation of the housing axis (18) with respect to the satellite. This eliminates using electrical output terrestrial magnetism sensing devices to sense direction finder/receiver orientation with respect to compass direction, and therefore avoids the inaccuracies and costs associated with such magnetism sensing devices.

Abstract: An improved cost-optimal state feedback control system for stabilizing the nertial reference platform in all-attitude inertial guidance systems which uses the "region" control concept. It reduces the computational requirements of cost-minimizing state feedback to within the capacity of aerospace vehicle onboard control processors. The control system iterates the feedback compensation process so as to reduce the R-gyro error to essentially a zero value and to prevent the gimbal assembly from entering a "gimbal lock" orientation.