Abstract: A fast lock circuit for phase lock loop comprising a frequency detector, a phase frequency detector, a logic unit and a corresponding charge pump for the frequency and the phase frequency detectors. Embodiments of the present invention use the logic unit to relay signals from the phase frequency detector circuit to the charge pump when the PLL is in lock. The logic circuit relay signals from the frequency detector circuit before the PLL is in lock. As a result, a constant current is supplied to a large loop filter capacitor before lock. In one embodiment, additional logic circuit may be used to maximize the output current. Therefore, using the logic circuit to supply constant current charges the large loop filter capacitor continuously and avoids a slow down in charging the large loop filter. Accordingly, current is no longer wasted and the lock time is improved.

Abstract: A voltage-controlled oscillator (VCO) comprising a first circuit, a second circuit, a comparator circuit, and a control unit. The first circuit can determine an output common mode voltage associated with an output of the VCO. The second circuit can generate an upper control voltage limit and a lower control voltage limit associated with a control voltage received by the VCO based, at least in part, on the output common mode voltage. The comparator circuit can compare the control voltage to the upper and lower control voltage limits. The control unit can determine whether to change a switched capacitance associated with the VCO based, at least in part, on whether the control voltage is outside the upper and lower control voltage limits, thereby maintaining an optimal region of operation for the control voltage.

Abstract: Methods and apparatus are provided for calibrating a voltage controlled oscillator, such as an N-stage voltage controlled ring oscillator. The voltage controlled oscillator comprises a power supply input and at least one gate delay element and has a frequency that is a function of a delay of the gate delay element and a voltage applied to the power supply input. A voltage controlled oscillator is calibrated by varying an output voltage of a programmable voltage source through a range of values; applying the output voltage to the power supply input of the voltage controlled oscillator; comparing an output clock frequency of the voltage controlled oscillator to a reference frequency clock for each of the output voltage values; and selecting a value of the output voltage that provides an approximate minimum frequency difference between the output clock frequency and the reference frequency clock.

Abstract: A semiconductor device includes a voltage control and oscillation circuit oscillating at a frequency according to a first control voltage to output an oscillation signal, a frequency/voltage conversion circuit receiving the oscillation signal from the voltage control and oscillation circuit and converting a frequency of the oscillation signal into a voltage, a control voltage generation circuit generating a new second control voltage having a level between that of the voltage converted by the frequency/voltage conversion circuit and that of a second control voltage generated previously, and an analog integration circuit integrating the second control voltage to generate the first control voltage and outputting the first control voltage to the voltage control and oscillation circuit.

Abstract: A calibration circuit (20, 50) and method (60) for calibrating the bias current of a VCO (10, 40) to minimize phase noise. The calibration circuit (20, 50) monitors the average voltage at the common-mode node of the VCO (10, 40) while varying the bias current over a predetermined range. The calibration circuit (20, 50) identifies the bias current associated with the minimum average common-mode voltage and utilizes this bias current for calibrating the biasing transistor of the VCO (10, 40).

Abstract: The present invention relates to a method for transmitting a two-valued signal via a channel, a pulse train being output after the change of a signal level of the two-valued signal, and subsequently to the pulse train, a backswing is output. The present invention also relates to a circuit configuration for transmitting a two-valued signal having a magnetically coupled coil pair which includes an input coil and an output coil, at least two driver stages which are each connected to a terminal of the input coil, and an evaluation circuit which is connected to the terminals of the output coil, a capacitance being provided between a driver stage and a terminal of the input stage, and the input coil and the output coil each include two coil sections having windings in the opposite direction, the coil sections having the same winding direction of the input coil and the output coil being magnetically coupled.

Abstract: Techniques for voltage controlled oscillator (VCO) circuits that are independent of temperature and process variations are described herein.

Abstract: A micro-oscillator in which the dispersion of center frequency, the interference between adjacent oscillator elements and the like are controlled and the resonance characteristic is excellent, and a semiconductor device including the micro-oscillator as well as a communication apparatus using a band-pass filter including the micro-oscillator, are provided. The micro-oscillator includes: a plurality of beam-type first oscillator elements 33 connected in parallel and a non-resonance beam-type second oscillator element 34 arranged between the first oscillator elements 33 adjacent to each other.

Abstract: A phase recovery circuit for avoiding noise interfering with the clock signal generated from an oscillator is disclosed. The phase recovery circuit includes a noise detector, a phase detector, and a phase locker. The noise detector detects noise and accordingly generates a noise detecting signal. The phase detector is triggered by the noise detecting signal for detecting the phase of the clock signal and accordingly generating a phase detecting signal. The phase locker locks the phase of the clock signal to a predetermined phase within a predetermined period after the occurrence of the noise detecting signal, and after the predetermined period, the phase locker releases the clock signal. In this way, the phase of the clock signal is not affected by noise.

Abstract: Device and method for temperature compensation in a clock oscillator using quartz crystals, which integrates dual crystal oscillators. The minimal power consumption is achieved through an efficient use of a processor in charge of the synchronization of the two oscillators. The invention is particularly adapted for the provision of a precise reference clock in portable radiolocalization devices.

Abstract: A temperature detection circuit (18) detects temperature around an oscillation circuit (20) equipped with voltage variable capacitors (23, 24). According to its temperature detection signal, a temperature compensation circuit (30) produces a voltage signal as a temperature compensation signal. That voltage signal is supplied to the voltage variable capacitors (23, 24) in order to sustain oscillation frequency of the oscillation circuit (20) at a substantially constant level. When a switch element (1) is, turned on by a non-TCXO signal, both terminals of each voltage variable capacitor (23, 24) are brought to the same potential (ground potential). Consequently, each voltage variable capacitor has a predetermined capacitance and temperature compensation function is made ineffective. In that state, initial frequency regulation is performed under normal temperature.

Abstract: A digital-controlled oscillator (DCO) is utilized in an all-digital phase-locked loop for eliminating frequency discontinuities. The DCO includes a tank module and a negative gm cell. The tank module comprises a plurality of cells, at least a portion of the cells comprising a first tracking set and a second tracking set for respectively handling an odd bit or an even bit. The odd bit and the even bit are related to an integer signal, a fractional signal or a combination thereof, the fractional signal is indicated by a primary voltage inputted to the DCO. With the DCO, frequency discontinuities and undesired spurs are eliminated.

Abstract: An oscillation circuit and the method for operating the same.

Abstract: A power supply circuit includes a first voltage regulator to generate a first supply voltage for a first circuit of a phase-locked loop and a second voltage regulator to generate a second supply voltage for a second circuit of the phase-locked loop. The first and second supply voltages are independently generated by the first and second voltage regulators based on the same reference signal. The first circuit may be a charge pump and the second circuit may be a voltage-controlled oscillator. Different circuits may be supplied with the independently generated supply voltages in alternative embodiments.

Abstract: The invention relates to pulse width modulator system (PWMS) comprising a modulator system input (MI),a modulator output (MO), an amplitude distribution filter (ADF) ,and a pulse width modulator (PMOD), wherein said amplitude distribution filter (ADF) establishes an intermediate output signal (OS) by modifying the level of the amplitude distribution of an input signal (IS) within at least one predetermined amplitude range of said input signal (IS), said input signal (IS) being received from said modulator system input (MI), and wherein said pulse width modulator (PMOD) provides a modulator output signal (MOS) on said modulator output(MO) on the basis of said intermediate output signal (OS).

Abstract: Techniques to compensate for nonlinearity of a tuning function of an oscillator are described. The tuning nonlinearity of the oscillator may be modeled as a disturbance input to the oscillator and may be compensated with an equal but opposite disturbance. In one design, a nonlinearity correction signal to compensate for the tuning nonlinearity may be generated, e.g., based on a phase error signal in a phase-locked loop (PLL) and a scaling factor determined adaptively. The nonlinearity correction signal may compensate for the n-th (e.g., second) order tuning nonlinearity, and an n-th order (e.g., squared) modulating signal may be used to derive the scaling factor and the nonlinearity correction signal. A control signal for the oscillator may be generated based on the nonlinearity correction signal and possibly one or more other signals. The control signal may be applied to the oscillator to adjust the oscillation frequency of the oscillator.

Abstract: A modulator for radio-frequency signals designed an entirely digital modulator has two mixer stages connected in series. The first mixer stage implements with a relatively low first sample rate a frequency mixing with a first oscillator frequency that is adjustable with high precision. The second mixer stage implements a frequency mixing with a significantly higher second sample rate and with a relatively coarsely adjustable second oscillator frequency. The downstream second mixer stage, in the case of a single mixer stage, the mixer stage, has at least two phase accumulators that are incremented with the higher second sample rate but with different incremental values. The output signal of at maximum one of the phase accumulators is evaluated at any point in time.

Abstract: In order to reduce noise on twisted metallic pair signal conductors, circuits are disclosed in which the signal balance between the wires of the pair is significantly improved, thereby reducing the line's susceptibility to external electromagnetic interference and equally reducing its ability to radiate signals into the surrounding medium. Further, the common mode impedance of the wire pair as seen at or close to the junction with the terminating equipment is controlled in order to reduce the ability of signals external to the wire pair to couple into the wire. This reduces noise in the line, as perceived by connected equipment, leading to an increase in the data carrying capacity of the line and the usable length of the line carrying such data.

Abstract: An embodiment of the present invention provides an apparatus, comprising a filter; and a matching network coupled to the filter, the matching network including a plurality of voltage tunable dielectric varactors.

Abstract: The present invention is directed to a method for making a hybrid material stripline device. The method includes providing an inner layer of material, the inner layer including a dielectric material and at least one conductive sheet. At least one stripline device is formed in the inner layer by processing the at least one conductive sheet. The at least one stripline device is characterized by a surface area footprint. A first exterior layer and a second exterior layer are provided. At least one of the first exterior layer and/or the second exterior layer includes at least one ceramic portion. The at least one ceramic portion has a ceramic surface area greater than or substantially equal to the surface area footprint of the at least one stripline device. At least one of the first exterior layer and/or the second exterior layer further includes a softboard dielectric material. The inner layer of material is sandwiched between the first exterior layer and the second exterior layer.

Abstract: A multilayer filter comprises an inductor stacked-layer portion and a varistor stacked-layer portion. The varistor stacked-layer portion has a varistor layer the main component of which is ZnO and a hot electrode and ground electrode positioned in opposite with the varistor layer intervening, and the region enclosed between the opposing hot electrode and ground electrode does not contain a Cu component. Because the region enclosed between the opposing hot electrode and ground electrode is a region which manifests varistor characteristics, and thus the region does not contain a Cu component, degradation of the attenuation characteristics can be suppressed.

Abstract: A system, apparatus and method for providing filtering functionality and impedance transformation within a BAW resonator network are disclosed. In particular, a BAW resonator network is designed to provide bandpass capability and a transformation between its input impedance and output impedance. By effectively integrating impedance matching functionality within the BAW resonator network, discrete impedance matching elements previously required within a system may be removed or reduced in size. As a result, matching networks and their associated component costs, insertion losses, and board size contributions may be reduced. Harmonic termination may be provided within the BAW resonator network or a prematch stage to improve efficiency of a power amplifier.

Abstract: According to some embodiments, a pre-poled, single-domain body of a ferroelectric crystalline material such as lithium tantalate or lithium niobate is electrically reduced by applying a voltage across the body in a non-oxidizing environment while the body is heated to a process temperature below its Curie temperature. The voltage generates an electric field along the polar axis of the body. Electrodes may be formed on the body surface by applying an acetate-based silver paint. Exemplary methods allow achieving electrical conductivity values of 10?11 to 10?9 Siemens/cm.

Abstract: A surface acoustic wave filter includes an acoustic track bounded by reflectors, at least a first input transducer and at least a second input transducer acoustically coupled to the acoustic track that are connected in parallel and connected to an asymmetric input port, at least two first output transducers acoustically coupled to the acoustic track that are connected in parallel and connected, to a first terminal of a symmetric output port and at least two second output transducers acoustically coupled to the acoustic track that are connected in parallel and connected to a second terminal of a symmetric output port. Each first output transducer in the acoustic track and corresponding second output transducers are side-by-side and are electrically connected in series via a first bus bar.

Abstract: A longitudinally coupled resonator acoustic wave filter device that utilizes an inter-IDT resonance mode with a reduced insertion loss has a structure in which apodization weights are assigned in first to third IDTs having narrow pitch electrode finger portions in portions other than the narrow pitch electrode finger portions, such that the electrode finger overlap width sequentially varies in an acoustic wave propagating direction in which an acoustic wave propagates, and portions of the IDTs located at ends adjacent to the narrow pitch electrode finger portions have a maximum electrode finger overlap width.

Abstract: An improved high frequency filter in a coaxial construction with one or a plurality of resonators has a thread pitch or thread pitch angle of an external thread of a thread-like tuning element which differs from the thread pitch or the thread pitch angle of the internal thread of the thread receiver at least in a partial portion of the length of the internal thread and/or of the external thread. The difference between the thread pitches or the thread pitch angles between the external thread of the thread-like tuning element and the internal thread of the thread receiver is more than 0.5%, and preferably 1% to 5%.

Abstract: An actively tunable waveguide-based iris filter having a first part including a first portion of a deformable iris filter cavity having an inlet and an outlet; a second part operatively coupled with the first part and including a second portion of the deformable iris filter cavity having a deformable membrane operatively coupled with the first portion of a deformable iris filter cavity; the first portion and the second portion together forming the deformable iris filter cavity of the tunable waveguide-based iris filter; and means for moving the deformable membrane, whereby movement of the deformable membrane changes the geometry of the deformable iris filter cavity for causing a change in the frequency of a signal being filtered by the filter. The tunable filter is fabricated using a MEMS-based process including a plastic micro embossing process and a gold electroplating process. Prototype filters were fabricated and measured with bandwidth of 4.05 GHz centered at 94.79 GHz with a minimum insertion loss of 2.

Abstract: A device includes at least one ultra-small resonant structure; and shielding constructed and adapted to shield at least a portion of said ultra-small resonant structure with a high-permeability magnetic material. The magnetic material is formed from a substance selected from a non-conductive magnetic oxide such as a ferrite; a cobaltite, a chromite, and a manganite. The magnetic material may be mumetal, permalloy, Hipernom, HyMu-80, supermalloy, supermumetal, nilomag, sanbold, Mo-Permalloy, Ultraperm, or M-1040.

Abstract: An RF MEMS switch and a method for fabricating the same are disclosed, in which the RF MEMS device is down driven at a low voltage using a piezoelectric effect. The RF MEMS switch includes a substrate provided with RF signal lines and a cavity, a cantilever positioned on the cavity, having one end fixed to the substrate, and a contact pad connecting the RF signal lines with the cantilever in contact with the RF signal lines when the cantilever is down driven.

Abstract: Provided is a device mounted contactor and a method of reducing continuous charge distribution, especially in a vehicle. The contactor includes a housing, and a plurality of power terminals. The device may further include a conductance shield and support structure extending from the housing. Situated at least partially in the housing is a switch, which is capable of electrically coupling at least two of the plurality of power terminals. One or more electrically insulative covers may be provided. The contactor may also provide a fused accessory terminal, which is electrically coupled to one of the power terminals through a fuse. A method according to the present invention reduces continuous electrical charge distribution in an electrical circuit by mechanically attaching a first contactor power terminal to a battery terminal and electrically coupling a second contactor power terminal to a circuit, which may include a vehicle starter.

Abstract: An electromagnetic transmission device. A guide bar connects to a fixed base and includes magnetic-permeable material and a first central height plane. A coil connects to the fixed base. A support base movably fits on the guide bar. An annular magnetic member connects to the support base and is surrounded by the coil. A magnetization direction of the annular magnetic member is perpendicular to a moving direction of the support base and annular magnetic member. The annular magnetic member includes a second central height plane. The coil interacts with the annular magnetic member to generate a first force. When moving to separate the second central height plane from the first central height plane, the annular magnetic member interacts with the guide bar to generate a second force, driving the support base and annular magnetic member to move along a direction perpendicular to the magnetization direction of the annular magnetic member.

Abstract: A system for improved magnetization of flexible magnetic sheet material, such as magnetic rubber. More particularly, this invention relates to providing a system for magnetization of pre-printed flexible magnetic sheet material.

Abstract: A magnet arrangement with a magnet coil system (M) with two coil systems (C, D) that are each arranged in a container (B1, B2) positioned around the z axis and that are axially mechanically separated by a split (G), wherein each coil system (C, D) comprises a first (C1, D1) and a second coil section system (C2, D2), wherein the first coil section systems (C1, D1) are exposed to attractive magnetic forces showing toward the split (G) (KC1, KD1) and the second coil section systems (C2, D2), to repulsive magnetic forces showing away from the split (G) (KC2, KD2), and containing in the split (G) at least one mechanical structure that withstands compressive loads (E1, E2) and that supports a part of the attractive magnetic forces (KC1, KD1), is characterized in that, in the split (G) within the dimensions of the containers (B1, B2), a mechanical structure (H1) is provided that mechanically withstands tensile loads in the z direction, supports a part of the repulsive magnetic forces in the axial direction (KC2, KD2

Abstract: The present invention provides a transformer apparatus configured by integrating an inverter transformer and balance transformer to be a downsized form, and a drive circuit using the transformer apparatus. The transformer apparatus comprises an inverter transformer having a core potion on which a primary coil and a secondary coil are wound, and a balance transformer having a core portion on which a primary coil and a secondary coil are wound, wherein the inverter transformer and the balance transformer are integrally formed by sharing a part of the core portions.

Abstract: An electric component includes a first base body that connects to a first contact, and an ally conducting element positioned along a current path between the first contact and a second contact. The electrically conducting element melts when an operating voltage of the electric component is exceeded. The electric component also includes an electrically insulating material that substantially surrounds the electrically conducting element and that is arranged so as to prevent an electric flashover between regions of the current path that are bridged by the electrically conducting element.

Abstract: An electronic component substrate (1-1) includes an insulating base (10) and a flexible circuit board (20) mounted on the insulating base (10). The flexible circuit board (20) is a synthetic resin film provided thereon with terminal patterns (29) and a conductor pattern (25) whose surface is slidingly contacted with a slider. The insulating base (10) is a synthetic resin molded piece. The flexible circuit board (20) is insert-molded to the insulating base (10). The electronic component substrate (1-1) is produced by preparing the flexible circuit board (20) and first and second mold members (41, 45) having a cavity (C1) with a shape that corresponds to the external shape of the electronic component substrate (1-1). Then, the flexible circuit board (20) is accommodated in the cavity (C1) between the first and second mold members (41,45), and the cavity (C1) is filled with a molten molding resin. After the molding resin has solidified, the first and second mold members (41, 45) are removed.

Abstract: A remotely or locally actuable refrigerator door lock has a body portion that is attached to the cabinet and a door portion that is attached to an edge of the door. A latch in the body portion engages a strike plate in the door portion and can be lifted out of engagement to open the refrigerator. The door lock assembly may be connected to a touch-screen device or via a USB or ethernet connection to a remote host computer. The host computer keeps an audit trail of the times and personnel accessing each refrigerator, and a temperature audit trail. The system may be used in hospital for controlling access to pharmaceuticals or may be used in a weight loss program. Temperature and humidity sensors are positioned within the refrigerator cabinet. The door lock may have battery power for portable or mobile applications.

Abstract: A digital communication system is disclosed, that allows a display of override content to interrupt a display of ongoing content on one or more display units. Ongoing content, such as advertisements, news, entertainment, or other relevant information, is provided on the display units until an urgent or security-related alert is required, and display of override content becomes necessary. Override content can include information relevant to the security of a passenger or passer-by viewing the display. Override content can relate to security threats such as accidents, major delays, fire, missing children, terrorist activity, or other content deemed adequately pertinent to warrant interrupting the display of ongoing content.

Abstract: A timing circuit that can function as an accurate persistent node in an RFID tag includes a power capture circuit for capturing power from a power source, and a counter circuit that provides a count representing a progression of time. The count can then be compared to a reference value representing a time constant of the circuit.

Abstract: When a reader of a Radio Frequency Identification (RF-ID) system sends out a command signal to the RF-ID tag and receives a response signal from the RF-ID tag, an End of Signal (EOS) of the received response signal is detected such that the next command signal can be transmitted within a time. Accordingly, response signal can be detected even under the environment of poor signal to noise ratio performance, and the EOS of the response signal from the RF-ID tag can be recognized with ease and speed.

Abstract: Remote monitoring and inspection of measurement devices, emergency equipment, parking spaces, and other items is accomplished by using a digital image sensor (e.g., a CMOS sensor) to capture a digital image containing information about the monitored item. A signal containing information about the digital image (e.g., data representing the captured digital image or data indicating the state of the captured digital image) is transmitted to a remote central station.

Abstract: A piezoelectric buzzer includes a housing unit, a buzzer unit, and first and second terminals. The housing unit includes first and second housings coupled together. The second housing includes a base plate and a pair of spaced apart insert seats, each of which protrudes inwardly from the base plate toward the first housing and is formed with an insert hole. The buzzer unit is disposed in the resonant chamber and includes a vibrating plate and a piezoelectric plate attached to the vibrating plate. The first and second terminals are inserted respectively into the insert holes of the insert seats, and have a respective connection section extending outwardly of the housing unit, and a respective extending section abutting against a respective one of the vibrating plate and the piezoelectric plate.

Abstract: A switching regulator for controlling transmit antennas of variable impedance, particularly transmit antennas of a keyless access authorization system in or for a vehicle, having an input terminal into which an antenna potential applied or appliable at the transmit antenna may be coupled, and having a control circuit designed to generate a compensation signal as a controlled variable for adapting the antenna potential to an actual output impedance and to establish a slope of the compensation signal depending on the actual antenna potential. The invention relates furthermore to a transceiver circuit with such a switching regulator and to a keyless access control system in or for a vehicle.

Abstract: The lighting system having a plurality of winker lamps disposed on front and rear portions of a vehicle body, a winker switch, and a lighting control circuit which performs changeover function allowing the winker lamps at a front portion of the vehicle body to lit as position lamps. The lighting control circuit is connected to a battery through an ignition switch. The lighting system further includes a power supply circuit which supplies, in an ignition off state, power to the lighting control circuit in response to an output signal from an antitheft apparatus to cause the winker lamps to light up or flicker. The output terminal of the antitheft device is connected to an electrical connection formed between the winker switch and the left and right rear lamps.

Abstract: A parking sensor apparatus has a microprocessor and multiple ultrasonic sensors. The microprocessor uses a time division transmitting method to control only one ultrasonic sensor to output an ultrasonic detecting signal. In addition, after one ultrasonic detecting signal is output, all ultrasonic sensor are controlled to be in receiving status. Therefore, the microprocessor receives the reflected detecting signals from the ultrasonic sensors and obtains preset distances defined between adjacent ultrasonic sensors to calculate the shortest distance between the vehicle and the obstacle. Further, since only one ultrasonic sensor outputs the ultrasonic detecting signal at a time point, the microprocessor clearly determines that the reflected detecting signal is corresponding to the present ultrasonic sensor, that is controlled to output the ultrasonic detecting signal.

Abstract: A system or method for monitoring a status of a member of a vehicle comprises a member of a vehicle. A set of one or more magnets is secured to the member. A magnetic field sensor is mounted on a vehicle, spaced apart from the member. The magnetic field sensor produces a data signal. A data processor receives the data signal from the magnetic field sensor and detects at least one of a deformation or movement of the member with respect to the vehicle.

Abstract: An accessory system suitable for use in an interior cabin of a vehicle includes an attachment element adhesively attached to an interior surface of a windshield of a vehicle, and an accessory module. The accessory module includes structure adapted to attach to the attachment element. The accessory module encompasses an antenna and a forward facing camera. The forward facing camera has a forward field of view through the windshield of the vehicle and in the direction of forward travel of the vehicle. The accessory system may include an image processor for processing image data captured by the forward facing camera. The forward facing camera may capture images for at least one of a collision avoidance system and an automatic headlamp control system.

Abstract: The object of the invention is to provide an improved vehicle display device that can avoid transmitting noise generated by vibration of a power source, as well as, can prevent the vibration of the power source from being transmitted into the other members or areas. The afore-mentioned object can be achieved by a vehicle display device comprising a circular dial member positioned in front of a display field of a display, at least partly surrounding the display field, and traveling linearly across the display field in cases where a movable member connected thereto is driven by a power source, the power source being coupled to a support member through a damper.

Abstract: The invention relates to a portable electronic device and computer software product. The portable electronic device comprises a motion detector for generating motion data characterizing the local movement of the portable electronic device, a motion intensity determiner for determining a instantaneous motion intensity value of the user of the portable electronic device from the motion data, and an active time counter for determining an active time accumulation that sums up the time periods, during which the instantaneous motion intensity value meets predefined activity criteria.

Abstract: A positioning and tracking system may comprise a monitoring station for receiving a location request and a user's identification code and transmitting a signal; a tracking device, which includes a signal receiver for receiving a signal from the monitoring station, including the user's identification code, a microprocessor/logic circuit for storing a first identification code, and generating a position signal; an erasable programmable read-only memory; a global positioning system logic circuit; a signal transmitter; and a plurality of transmitter/receiver stations for communicating between the tracking device and the monitoring station; wherein the tracking device compares the user's identification code to the stored identification code and upon determining that the user's identification code matches the stored identification code, the signal transmitter transmits the position signal to the monitoring station.