Abstract: A clock distribution circuit and a method thereof. The clock distribution circuit comprises a comparator, a filter, a scaling unit, and an oscillator. The comparator compares a reference signal and a feedback signal to generate an error signal. The filter is coupled to the comparator and outputs a filtered signal based on the error signal. The scaling unit is coupled to the comparator, and scales down the filtered signal by a scaling factor to form a control signal. The oscillator is coupled to the scaling unit, and produces the feedback signal based on the control signal. And the scaling factor is less than 1.

Abstract: Improved voltage controlled oscillator circuits and phase-locked loop circuits are disclosed. For example, a voltage controlled oscillator circuit comprises a first linear amplifier, the first linear amplifier generating a coarse-tuning voltage from an input voltage, a second linear amplifier, the second linear amplifier generating a fine-tuning voltage from the input voltage, and a voltage controlled oscillator comprising a coarse-tuning input coupled to the first linear amplifier, a fine-tuning input coupled to the second linear amplifier, and a clock signal output, wherein a frequency of a signal on the clock signal output is changeable as a function of the input voltage. Such a voltage controlled oscillator circuit may be employed in a phase-locked loop circuit.

Abstract: An oscillator circuit that generates an oscillation signal is provided. The oscillator circuit includes an oscillator that generates the oscillation signal based on positive feedback of a signal, a synchronization signal generating section that generates a compulsory synchronization signal having an edge that (i) crosses a zero cross point at an ideal timing of an edge of the oscillation signal every predetermined number of cycles of the oscillation signal and (ii) has a gradient in the same direction as the edge of the oscillation signal, and a combining section that injects the compulsory synchronization signal into a positive feedback path of the oscillator.

Abstract: A method and programmable oscillator model are provided for implementing high frequency clock generation for a simulation environment. The programmable oscillator model includes an internal ring oscillator for generating a high frequency clock. The internal ring oscillator counts a number of clocks and determines when to switch the reference clock. For example, a clock edge time is recorded as a two-byte field, where a high byte records a programmable number of fast clocks per clock edge, and a low byte records a fraction of a clock edge. Each time the reference clock switches a count down counter is loaded with the high byte, and the low byte is added to the current fraction. If the fraction has a carry, an additional fast clock is added to the count down counter.

Abstract: A controllable oscillator includes an output oscillation adjust module operably coupled to an oscillator for producing an effective output oscillation based on an oscillation control signal. The output oscillation adjust module includes an output select block that produces the effective output oscillation from a sequence of selected taps from the plurality of taps of the oscillator. A tap adjust control generator, responsive to the oscillation control signal generates a sequence of tap adjust control signals that command the output select block to select the sequence of selected taps from the plurality of taps. The tap adjust control generator includes an integrator having an integrator output, responsive to the oscillation control signal and a modulo(x) module for producing the sequence of tap adjust control signals based on the integrator output.

Abstract: A device for generation of a reference frequency includes a component configured for generating a reference voltage, and a slaving circuit configured for slaving the reference frequency to the reference voltage.

Abstract: A particle beam generator has a vacuum chamber, a magnet which generates a constant magnetic field in the vacuum chamber, acceleration electrodes which generates a magnetic field in a direction perpendicular to the direction of the magnetic field generated by the magnet in the vacuum chamber, a take-out electrode which takes out charged particles accelerated in the vacuum chamber; and a target cell provided at a position at which the charged particles taken out by the taken-out electrode strikes. At least a part of surfaces exposed to the charged particles of the vacuum chamber, the acceleration electrodes, the take-out electrode and/or the target cell is made of a material including an element having atomic number larger than copper.

Abstract: Embodiments of High-Power Millimeter-Wave Oscillators are generally described herein. Other embodiments may be described and claimed. In some embodiments, the oscillator includes a polarized partial reflector to at least partially reflect back signals to a reflection array amplifier to help induce oscillation by individual sub-array amplifier elements of the reflection array amplifier. In some other embodiments, the oscillator includes a phase-graded polarization-sensitive reflection plate to at least partially reflect back signals to the reflection array amplifier to help induce an oscillation by the sub-array amplifier elements. In some embodiments, the oscillator includes a reflector and a phase-graded polarized reflection-transmission plate to at least partially pass through signals to the reflector for reflection back to the reflection array amplifier to help induce an oscillation by the sub-array amplifier elements.

Abstract: A resonator includes a vibrator that performs mechanical vibration, an exciting unit that applies an exciting force to the vibrator, and a modulating unit that modulates a spring property of the vibrator. The vibrator vibrates when the exciting force is applied to the vibrator from the exciting unit. The modulating unit modulates the vibrator according to the exciting force.

Abstract: A method for manufacturing a quartz oscillator having a stable temperature drift characteristic attributed to the quartz oscillating piece and a quartz oscillator are disclosed. The method comprises a quartz crystal etching step S1 of processing a quartz oscillating piece into a predetermined shape by etching, an electrode membrane forming step S2 of forming an electrode on the quartz oscillating piece, a quartz crystal mounting step S3 of mounting the quartz oscillating piece in an oscillator package, a leakage oscillation adjusting step S4 of driving the mounted quartz oscillating piece, detecting the leakage oscillation, and removing a part of the quartz oscillating piece depending on the detected leakage oscillation, and a re-etching step S6 of re-etching the quartz oscillating piece subjected to the removal.

Abstract: Embodiments of the present invention include a common-gate amplifier having an input terminal and an output terminal, a transistor having a source, a drain, and a gate, four inductors, and two capacitors, and a negative amplification circuitry. The negative amplification circuitry has an input terminal to receive an RF signal. The negative amplification circuitry applies negative or zero amplification to the RF signal and outputs the negative or zero amplified signal on an output terminal. Alternative embodiments include a Colpitts differential oscillator, which includes two Colpitts single-ended oscillators. Each Colpitts single-ended oscillator includes a transistor. The source of the transistor in one Colpitts single-ended oscillator may be capacitively coupled to the gate of the transistor in the other Colpitts single-ended oscillator.

Abstract: Placing inductors or resistors in parallel causes the combined value of inductance or resistance to decrease according to the parallel combination rule. This invention decreases the parasitic resistance of an inductor by placing several inductors in parallel. Furthermore, by careful placement of these inductors, the mutual inductance between these inductors can be used to increase the equivalent inductance value to a value near that of the original inductance value of a single inductor. Thus, it is possible to create an inductance with a much lower value of parasitic resistance. This invention allows the formation of high Q inductors and would be beneficial in any circuit design requiring inductances. Another aspect of this invention is that the coils can be partitioned to minimize eddy current losses. This invention can easily be implemented in a planar technology. Simulations of several tank circuits indicate that the power dissipation can be reduced 3 to 4 times when compared to conventional techniques.

Abstract: A crystal oscillator emulator integrated circuit comprises a first temperature sensor that senses a first temperature of the integrated circuit. Memory stores calibration parameters and selects at least one of the calibration parameters based on the first temperature. A semiconductor oscillator generates an output signal having a frequency, which is based on the calibration parameters, and an amplitude. An amplitude adjustment module compares the amplitude to a predetermined amplitude and generates a control signal that adjusts the amplitude based on the comparison.

Abstract: A demodulator for processing a PWM (pulse width modulation) signal includes a variable capacitor, a charging unit, a discharging unit, and a tuner. The charging and discharging units charge or discharge the variable capacitor depending on the PWM signal. The tuner determines a capacitance of the variable capacitor and a discharge current of the discharging unit for proper operation of the demodulator in various RF environments.

Abstract: The present invention is directed to a balun that includes a first coupler structure having a first port of a balanced port pair and an unbalanced port. A second coupler structure includes a second port of the balanced port pair. The second coupler port structure being connected to the first coupler structure such that the second port of the balanced port pair is DC isolated from the first port of the balanced port pair without decoupling components.

Abstract: An impedance conversion device has four conductors arranged so that the first and second conductors form a transmission line having a first characteristic impedance, the third and fourth conductors form a transmission line having the first characteristic impedance, the first and third conductors form a transmission line having a second characteristic impedance, and the second and fourth conductors form a third transmission line having the second characteristic impedance. The second and fourth conductors are interconnected at proximate ends through a resistance equal to the first characteristic impedance. The third and fourth conductors are interconnected at proximate ends through a resistance equal to the second characteristic impedance. The lateral dimensions of the impedance conversion device are small enough to permit insertion in a stacked pair line.

Abstract: A method and apparatus for producing a distributed plasma at atmospheric pressure. A distributed plasma can be produced at atmospheric pressure by using an inexpensive high frequency power source in communication with a waveguide having a plurality particularly configured couplers disposed therein. The plurality of particularly arranged couplers can be configured in the waveguide to enhance the electromagnetic field strength therein. The plurality of couplers have internal portions disposed inside the waveguide and spaced apart by a distance of ½ wavelength of the high frequency power source and external portions disposed outside the waveguide and spaced apart by a predetermined distance which is calculated to cause the electromagnetic fields in the external portions of adjacent couplers to couple and thereby further enhance the strength of the electromagnetic field in the waveguide. Plasma can be formed in plasma areas defined by gaps between electrodes disposed on the external portions.

Abstract: A bulk acoustic wave device includes an acoustic decoupler between first and second film bulk acoustic resonators (FBARs). The first FBAR is resonant at a resonant frequency of the device and includes first and second planar electrodes abutting opposite sides of a first resonator volume free of any intervening electrodes and containing piezoelectric material disposed for acoustic vibrations parallel to a propagation axis normal to the first and second electrodes. The first FBAR has a first electrical impedance parallel to the propagation axis. The second FBAR is resonant at the resonant frequency and includes third and fourth planar electrodes abutting opposite sides of a second resonator volume free of any intervening electrodes and containing piezoelectric material disposed for acoustic vibrations parallel to the propagation axis. The second FBAR has a second electrical impedance parallel to the propagation axis and different from the first electrical impedance.

Abstract: An elastic boundary wave device includes an IDT including laminated conductor layers disposed between a first medium and a second medium, wherein a plane that divides the IDT in half in the thickness direction defines an interface, the energy of an elastic boundary wave present on the side of the first medium of the interface is denoted as E1, and the energy of an elastic boundary wave present on the side of the second medium of the interface is denoted as E2, and wherein if the IDT included only a conductor having the highest density among the laminated conductor layers of the IDT, when the energy of an elastic boundary wave present on the side of the first medium of the interface is denoted as E1? and the energy of an elastic boundary wave present on the side of the second medium of the interface is denoted as E2?, the energies of an elastic boundary wave would satisfy the relationship of E1/E2<E1?/E2? so that the sonic velocity of an elastic boundary wave in the IDT including the laminated conductor lay

Abstract: A high frequency filter incorporates first to third resonators provided inside a layered substrate. The first and third resonators are adjacent to each other and inductively coupled to each other. The second and third resonators are also adjacent to each other and inductively coupled to each other. The first and second resonators are not adjacent to each other but are capacitively coupled to each other through a conductor layer for capacitive coupling. The conductor layer for capacitive coupling incorporates: a first portion for forming a first capacitor between itself and the first resonator; a second portion for forming a second capacitor between itself and the second resonator; and a third portion having an end connected to the first portion and the other end connected to the second portion, the ends being opposed to each other in the longitudinal direction. The width of at least part of the third portion is smaller than the width of each of the first portion and the second portion.

Abstract: A transmission line having a slot line with a slot formed on a front surface electrode on a dielectric substrate, and two such slot lines are positioned with the front surface electrodes separated from one another with a gap therebetween. A slot resonator with one end open at the gap side is provided at the front edge side of each slot line, and these slot resonators are positioned so as to be capable of coupling to one another. A slot stub which is branched out from the gap side is provided on each front surface electrode. Thus, leakage of a high-frequency signal in the gap can be suppressed with the slot stub.

Abstract: A dimmer switch for controlling a light includes a wheel assembly, a rotational motion detector and a dimmer control. As the wheel assembly is rotated, the light is dimmed. An on/off control is responsive to a push detector for detecting whether the wheel assembly has been pushed. The on/off control controls where the light is on or off.

Abstract: An electromechanical switch, includes a substrate, a beam which is mounted on the substrate at both end parts thereof, a first driving electrode which is provided on the beam, a first signal transmitting electrode which is provided on the beam and is electrically separated from the first driving electrode, a second driving electrode which is provided on the substrate and pulls in the first driving electrode when the electric potential is applied between the first driving electrode and the second driving electrode, a second signal transmitting electrode which is provided on the substrate, and is brought into contact with the first signal transmitting electrode when the first driving electrode is pulled in the second driving electrode, the second signal transmitting electrode being electrically separated from the second driving electrode, and a fixed electrode which is formed so as to have electrostatic power with respect to the first driving electrode, and pulls in the first driving electrode so as to separate

Abstract: An injection valve includes a housing that movably accommodates a needle. A movable core is axially movable together with the needle in the housing. A stationary core is fixed in the housing for forming a magnetic circuit together with the movable core. At least one of the movable core and the stationary core has an end that has an annular first protrusion protruding toward an end of an other of the movable core and the stationary core. At least one of the movable core and the stationary core has an end that has an annular second protrusion protruding toward an end of an other of the movable core and the stationary core. The first protrusion is substantially coaxial with respect to the second protrusion.

Abstract: A microswitching device includes a base, a fixed portion joined to the base, a movable portion extending along the base and having a fixed end fixed to the fixed portion, a movable contact electrode film provided on a side of the movable portion opposite the base, a pair of fixed contact electrodes joined to the fixed portion and having a region opposing the movable contact electrode film, a movable driving electrode film provided on a side of the movable portion opposite the base, and a fixed driving electrode having a region opposing the movable driving electrode film. The movable driving electrode film is thinner than the movable contact electrode film. The fixed driving electrode is joined to the fixed portion joined to the base.

Abstract: A magnetically actuated apparatus, which enlarges, extends and makes continuous magnetic fields used by magnetically controlled devices, such as a magnetic reed switch for use in physical security monitoring systems is shown. Apparatus includes a sensor and a magnetic actuator for use with a movable closure member. The sensor is mounted into to a fixed support member that is arranged for displacement relative to a second movable support member. The sensor has a pair of contacts that are connectable to an electronic circuit. The contacts form a switch that is actuated by the magnetic actuator. The magnetic actuator comprises a unique elongated magnet with specific polarity or a plurality of aligned, alike permanent magnets that are mountable to the second support member.

Abstract: A microelectrical mechanical system (MEMS) actuator having electrically conductive coils that create first magnetic fields that are opposed by a second magnetic field is disclosed. The actuator includes two coils having dual, interspersed Archimedean spirals. Within an actuator, one coil is arranged with spirals that proceed clockwise, while the other coil is provided with spirals that proceed counterclockwise. An electrically conductive bridge mechanically couples the two coils of each actuator to a mirror. Opposing magnetic fields are created to provide a force that urges the coils to expand so that the outermost portions of the coil extend upward, away from the substrate, and lift the bridge and mirror. Control current may then be modulated to increase and decrease the coil's magnetic field strength thereby increasing and decreasing the coil's extension to raise and lower relative to the substrate.

Abstract: A solenoid valve actuator includes a coil bobbin having a coil disposed therein and a bushing body receiving aperture. A flux plate is connected to a first end of the coil bobbin and includes a flux plate surface area. A bushing is positioned between the flux plate and the coil bobbin. The bushing includes a flange portion having a flange area substantially equal to the flux plate surface area, and a body portion integrally joined to the flange portion and extending substantially perpendicular to the flange portion. An armature is slidably received within the receiving aperture of the bushing body portion.

Abstract: A inductance variable device includes a first inductor, a second inductor magnetically coupled to the first inductor, a current source whose current is variable, electrically connected to the first inductor, and a current control unit. The current control unit controls a current flowing from the current source to the first inductor according to a feedback signal having frequency information in a current flowing in the second inductor to vary a combined inductance of the second inductor.

Abstract: An electrical coil includes first and second electrically-conductive elements each of a thin, flat, annular configuration formed with a gap to define the turns of a 2-turn coil, and an electrically insulative element also of a thin, flat, annular configuration disposed coaxially between the two electrically-conductive elements and formed with a gap aligned with one end of each turn to permit the ends to be electrically connected together. Also described is a transformer having a secondary winding including a plurality of such 2-turn coils, and a primary winding of a plurality of double-coils each connected together at their mid-portions.

Abstract: An inductive coupler provides an interface between a power line and a communication device which communicates via the power line. The power line operates at a potential between four and 140 kilovolts while accommodating a current having a frequency between 45 and 65 hertz, and the communication device operates substantially at ground potential. The inductive coupler includes a split ferrite core having material selected to provide a substantially flat frequency response between one and 50 megahertz. The coupler also includes a clamping mechanism allowing the inductive coupler to clamp around the power line or around a utility line connected to the power line. Further, the coupler includes at least one lead for communicatively connecting the inductive coupler to the communication device. The inductive coupler forms an air gap when the inductive coupler is clamped. If the coupler is insulated, the insulation is also used for the air gap.

Abstract: A monolithically integrated circuit, particularly an integrated circuit for radio frequency power applications, has a transistor (11; 51), preferably a power LDMOS transistor, and a spiral inductor (12; 26; 41; 52, 53), preferably an RF blocking inductor. The spiral inductor is arranged on top of the transistor, whereby an electromagnetic coupling between the spiral inductor and the transistor is not typically possible to avoid. However, the transistor has a finger type layout (13a-k, 14a-f) to prevent any significant eddy currents caused by the electromagnetic coupling from occurring. The chip area needed for the circuit is strongly reduced by such an arrangement.

Abstract: A high-current electrical coil includes a plurality of flat, electrically-conductive strips bent to define together a coil in which the electrically-conductive strips are disposed coaxially and extend longitudinally with respect to the longitudinal axis of the coil. Each of the electrically-conductive strips is bent to define at least a part of a turn of the coil. One electrically-conductive strip has an outer end carrying a first connector terminal for the coil and projecting outwardly of the coil; and another electrically-conductive strip has an outer end carrying a second connector terminal for the coil and projecting outwardly of the coil. Each of the electrically-conductive strips includes inner ends in electrical continuity with each other, and intermediate portions electrically-insulated from each other such that the plurality of electrically-conductive strips together define a coil exceeding one turn between the first and second connector terminals.

Abstract: A multiple phase buck converter or boost converter, or buck-boost converter has an inductor in each phase. The inductors are inversely coupled. In a first embodiment, the converter includes a toroidal magnetic core with inductors extending under and over opposite sides of the toroidal magnetic core. The coupled inductors are thereby inversely coupled and have a relatively low ohmic resistance. In a second embodiment, the converter comprises a ladder-shaped magnetic core (i.e. having parallel sides, and connecting rungs). In this case, the inductors extend under the sides, and over the rungs. Each inductor is disposed over a separate rung. The ladder-shaped magnetic core is preferably disposed flat on a circuit board. Inverse coupling and low ohmic resistance are also provided in the second embodiment having the ladder structure.

Abstract: A bandpass filter includes at least two thin-film layers, a first resonant circuit including a first inductor, and a second resonant circuit including a second inductor. In one embodiment, the first inductor comprises a coil having a counter-clockwise rotation positioned in two or more of the at least two thin-film layers and the second inductor comprises a coil having a clockwise rotation positioned in two or more of the at least two thin-film layer. In this case, the first inductor is coupled to the second inductor in at least one of the at least two thin-film layers when the bandpass filter is energized. In another embodiment, the first inductor has a clockwise rotation and the second has a counter-clockwise rotation positioned. In this case, the first inductor is coupled to the second inductor in at least two of the at least two thin-film layers when the bandpass filter is energized.

Abstract: In accordance with the invention, a tiled periodic metal film sensor can be used to measure refractive index changes of a thin layer of liquid to determine changes in the liquid composition. The tiled periodic metal film sensor senses reflected light as a function of wavelength and infers a change in the refractive index of the fluid.

Abstract: Device for remote operation of rotary potentiometers consisting of a mounting bracket 10 supporting a flexible drive shaft 24 which has affixed to its supported end a control knob 2 and at its unsupported end a universal joint 26 which houses a thumb-screw 30 for capture of a rotary potentiometer shaft. Thus allowing the user to operate floor-mounted effects devices from a more natural standing position during a musical performances, rather than having to crouch down during said performance.

Abstract: The invention discloses a variable attenuator, comprising two or more resistors each resistor having its own effective resistance value, and means for simultaneously short circuiting at least a portion of two or more of said resistors, whereby simultaneously changing the effective resistance values. The variable attenuator of the invention is suitable for use in various high frequency and microwave circuits and systems, and has the features of a wide frequency band, small size, easy fabrication, low cost, and so on.

Abstract: An in vehicle device transfers connection information to a power management device, the connection information indicating whether the in-vehicle device can communicate with the power management device. The in-vehicle device either transfers condition information to the power management device, the condition information indicating that the in-vehicle device is ready for turning off, or sets the in-vehicle device to not communicate with the power management device when a predetermined condition is met, the predetermined condition indicative of an inability of the in-vehicle device to transfer information to the power management device. The power management device requests the connection information from the in-vehicle device and requests the condition information from the in-vehicle device.

Abstract: The invention concerns a redundant computerizing system comprising additionally to a master programmable automaton and a standby programmable automaton, a computerized monitoring device enabling a memory image of the comparison process concerning a certain number of output signals of the computerizing system to be set up.

Abstract: A composite electronic apparatus that prevents misoperation of a remote control device and provides easy remote control operations for electronic devices is provided. When a DVD mode switching key is pressed, for example, in this composite electronic apparatus, a DVD recognition LED is turned on. When a VCR mode switching key is pressed, a VCR recognition LED is turned on. In addition, when one of action command keys is pressed, the DVD recognition LED or the VCR recognition LED indicating an operation target is turned on in accordance with information indicating a transmission mode stored until the action command key is operated.

Abstract: An input unit for a field device, has a registering unit for an electronic identifier of a user, which enables a definite identification of the user.

Abstract: A system for receiving data for training a trainable transmitter used to subsequently transmit a modulated RF signal having the received data includes an antenna, a capacitive detection circuit and a control circuit. The capacitive detection circuit is coupled to the antenna and configured to detect data provided in a control signal of a remote control transmitter used to remotely actuate a device. The control circuit is coupled to the capacitive detection circuit and is configured to store the received data and to generate the RF signal having the received data to be transmitted by the trainable transmitter to actuate the device.

Abstract: A universal remote control interacts with a user to assist in training to one or more appliances. If the appliance is activated by a rolling code activation signal, a sequence of different rolling code activation signals is transmitted until the user indicates a successful transmission. If the appliance is activated by a fixed code activation signal, a fixed code word is used to generate and transmit each of a sequence of different fixed code activation signals until the user indicates a successful transmission. At least one of the sequences of activation signals inserts a preset amount of time after each activation signal transmission. If user input is not received within the preset amount of time, the next activation signal in the sequence is transmitted.

Abstract: The invention relates to a device for actuating a vehicle door locking system, having a portable identification unit (10) and a vehicle-mounted control device (20) which, when the identification unit moves closer, generates, on the basis of the result of a contactless data communication between the control device and the identification unit for checking the access authorization for the identification unit, a control signal for unlocking the vehicle door locking system if the presence of the access authorization for the identification unit has been detected.

Abstract: An actuation control system is disclosed that includes an actuator that is operatively associated with an actuator device, and a key for operating the actuator. The actuator and the key are arranged in use to be wirelessly coupled, and the actuator is arranged in use to derive the electrical energy for actuating the device from the key.

Abstract: An improved electronic lock with keyless, cardless digital key system and integrated facilities management and administration system is provided for use in multi-unit buildings, particularly in hospitality industry. The present invention relates generally to a network architecture that integrates a wireless communication network device operating a plurality of electronic locks, and the all-inclusive property administration and management system in a multi-unit facility such as a hotel or a condominium.

Abstract: Vehicle modular security system having an authentication device for generating authentication signals, an authenticating apparatus at a vehicle for receiving the authenticating signals from the authenticating device and generating validation signals, a master controller at the vehicle for receiving the validation signals from the authenticating apparatus and generating control signals, at least one slave controller module at the vehicle for receiving the control signals from the master controller and generating security restriction signals, and modified circuits at the vehicle for receiving the security restriction signals from the at least on slave controller and deteriorating a capacity of the vehicle to be used.

Abstract: A fingerprint table or other type of data structure including a plurality of entries may be provided, each entry including a transmitter fingerprint set of a respective network location. Determining whether a current network location is a network location known to a user device may include comparing a determined transmitter fingerprint set of the entity with the transmitter fingerprint set of one or more fingerprint table entries. A user interface may be provided that enables a user to control when a transmitter fingerprint set is determined, compared with fingerprint table entries and/or recorded.

Abstract: In a meeting or group event, people having a portable device, such as a cell phone or pager, may wish to be discretely notified when an important message is received, an urgent call comes in from a selected person or a selected group of people, or to be alerted to an upcoming important event without any audible alert to disturb the meeting or group event. To convey such a notification, a tactile alert is provided by vibrating the portable device according to a unique vibration pattern associated with the received communication. When a communication is received, a group identification (ID) is assigned based on the communication being a member of a classified group of source addresses. The portable device associates the group ID with a unique vibration pattern. To provide the alert, the portable device is vibrated according to the unique vibration pattern.