Abstract: An apparatus for stabilizing a boosted voltage includes a voltage detector, a buffer driver control unit and a buffer driver. The voltage detector detects a change in a level of a boosted voltage and outputs first through N-th detection signals corresponding to the detected change, the boosted voltage being generated to have a higher voltage level than a power supply voltage level in response to a clock signal. The buffer driver control unit generates first through 2N-th current control signals based on the first through N-th detection signals. The buffer driver includes first through N-th inverter drivers that selectively operate based on the first through 2N-th current control signals, thereby modulating a charging current for generating the boosted voltage. Hence, the boosted voltage having a constant level and a reduced ripple may be generated.

Abstract: A passive charge pump includes a plurality of stages or a single stage, with each stage including only two MOS transistors. Both of the transistors are configured in a transcapacitance configuration, and both transistors are primarily in the accumulation mode during operation. Embodiments of the charge pump rely entirely on the MOS capacitance and its embedded diode features to perform the necessary charge accumulation and transfer process necessary for voltage multiplication at the output and do not require any collateral capacitors and diodes. The charge pump may be embodied in an MOS technology, nMOS, pMOS, or CMOS.

Abstract: The charge pump circuit includes: a charge pump output branch; a current leakage device coupled to the output branch; and a feedback device coupled between the output branch and a control node of the current leakage device such that the leakage device cancels leakage current from the output branch.

Abstract: Linear power amplifiers tend to be inefficient. This is a particular problem for RF amplifiers in a cellular base station. In order to improve the efficiency of such amplifiers, attempts have been made to modulate the power supply to the amplifier proportional to the envelope of the signal to be amplified. An UMTS signal requires power supply modulation at frequencies of the order of 10 to 20 megahertz. When quantization noise is taken into account, oversampling becomes desirable. However, switching power supplies at frequencies of the order of 40 or 80 or even 160 megahertz becomes difficult. By modifying the coding of phases of the power supply to be switched so that the number of phases enabled is proportional to the desired power supply output voltage rather than the length of a pulse in a time domain on any particular phase being proportional to the output voltage, dramatic improvements are achieved in switching losses, balance between phases and accurate tracking of the input signal.

Abstract: Apparatus and methods for driving multiple output stages with a single switching amplification modulator reduce system cost and complexity. The technique also addresses applications wherein one or more of several output stages of potentially differing output powers are desired at one time. That is, the switching drivers and loads can be the same or different.

Abstract: A power amplifier comprises an amplification stage comprises a plurality of amplifiers, wherein each amplifier provides an amplified output, and an inductive summing device configured to receive the plurality of amplified outputs and provide a combined output signal. A method of amplifying a signal comprises applying the signal to an amplifier stage comprising a plurality of amplifiers, wherein each amplifier is configured to provide an amplified output, and providing a combined output signal via an inductive summing device configured to receive the plurality of amplified outputs.

Abstract: A power amplifier includes an input network, output stages, coupled in parallel and configured to output power optimally in corresponding power-ranges, the output stages coupled to the input network, an output impedance matching network, coupled to the output stages and not containing a switching element, and a bias-control network, coupled between the output impedance matching network, the input network, and the output stages. In some amplifiers the output impedance matching network does not contain a switching element corresponding to the output stage configured to output power in the highest range. In other amplifiers the bias-control network is configured to isolate output stages by providing a hard shut-off to transistors of the isolated output stages.

Abstract: A fast search algorithm for loop alignment of a feed forward amplifier is disclosed. The algorithm controls a processor that adjusts, digitally, the gain and phase of the loop alignment based on power measurements at the input and output of cancellation combiners, to find the optimal setting. A “non-collinear descent” algorithm is used to search, iteratively, for the minimum within an error surface. For loop alignment, the error surface is defined by the set of measurement points comprising the alignment settings and the associated cancellation residuals. For the case of first loop alignment, the cancellation residual is measured using the ratio of two power detectors located at the input and after the cancellation (error) combiner. For second loop alignment, cancellation is estimated using the residual pilot power detected at the output of the amplifier. The preferred alignment method uses three successive measurements to estimate the gradient direction with respect to gain and phase shifter settings.

Abstract: A class D switching amplifier has a pulse width modulator that drives a speaker. The amplifier includes an over-current protection circuit, which includes current-monitoring MOSFETs that are each in parallel with one of four power MOSFETs. Signals taken from one side of the current-monitoring MOSFETs go to a logic circuit that removes the amplifier input circuit when the logic circuit indicates that an over-current condition is present. Current through the current-monitoring MOSFETs also goes through the speaker, thus improving amplifier efficiency.

Abstract: An electronic class-D amplifier including a one servo-loop amplifier plus pulse width modulator, and a controlled delay stage including a delay modulation input, and a negative feedback path connects an output of the output switching stage to an input of the servo-loop amplifier wherein the forward gain of an output switching stage, the forward gain of the servo-loop amplifier plus pulse width modulator and controlled delay stage, and a carrier reference output signal's mean frequency, and modulation gain of the controlled delay stage, and the gain of the negative feedback path, are selected to lower the distortion of a signal at the amplifier output relative to a signal applied to the amplifier input.

Abstract: A rail-to-rail-Input Buffer with constant mutual conductance includes a differential input; a first differential stage supplied with a first reference current; a second differential stage supplied with a second reference current; a switching PMOS-transistor which switches through when the input signal is higher than a first threshold voltage to divert the first reference current to a first current mirror circuit; a switching NMOS-transistor which switches through when an input signal is lower than a second threshold voltage to divert the second reference current to a second current mirror circuit; a third differential stage supplied with the mirrored first reference current and replaces the first differential stage when the input signal is higher than the first threshold voltage; and a fourth differential stage supplied with the mirrored second reference current and replaces the second differential stage when the input signal is lower than the second threshold voltage.

Abstract: A differential feedback system that minimizes even order distortion of a differential circuit. The feedback system includes a feedback circuit for use with a differential circuit to reduce even-order distortion and dc offset of a difference output signal produced by the differential circuit. The feedback circuit includes an integrator coupled to receive the difference output signal from the differential circuit and produce an integrator output signal. The feedback circuit also includes a control circuit coupled to the integrator to receive the integrator output signal to produce a control signal that is coupled to the differential circuit, wherein the control signal controls the differential circuit to reduce the even-order distortion and the DC offset.

Abstract: A radio-frequency amplifier is provided. The radio-frequency amplifier includes a transistor having an input terminal, an output terminal, a control terminal, and a transconductance gm. A series-connected feed-through resistance Rf and feed-through capacitance Cf is connected in parallel with the input terminal and the output terminal of the transistor. A load resistance RL is connected to the output terminal. The control terminal of the transistor is biased at a fixed voltage. Part of the transistor noise follows the looped path through the feed-through resistor instead of passing on to the load, which reduces the noise figure of the amplifier. The value of gm, Rf and RL are chosen in a way to keep the input impedance of the amplifier matched to a well-defined signal source impedance.

Abstract: Provided a method of reducing impedance variations in an electrical circuit structured and arranged for placement on an integrated circuit (IC) substrate. The method includes forming sets of parallel connected resistors, each set corresponding to one of the impedance devices on the IC. Each set also includes two or more parallel resistor paths, each resistor path including two or more cascaded resistors and has a total impedance value substantially equal to the predetermined impedance value of its corresponding impedance device. Finally, the method includes configuring the sets of parallel resistor paths to form an interdigital structure across the substrate when the electrical circuit is placed on the IC.

Abstract: The invention provides a method for reducing power dissipation in a power amplifier used in wireless communication systems, said power amplifier having transistors showing a quiescent current, wherein the quiescent current of the power amplifier is adaptively changed according to the average output power of the power amplifier. A power amplifier for use in wireless communication systems is provided, said power amplifier having transistors showing a quiescent current, comprises adaptive biasing means changing the quiescent current of the power amplifier in accordance with the average output power of the power amplifier for reducing power dissipation in the power amplifier. A UMTS hand set comprises a power amplifier as specified above.

Abstract: A cross-differential amplifier is provided. The cross-differential amplifier includes an inductor connected to a direct current power source at a first terminal. A first and second switch, such as transistors, are connected to the inductor at a second terminal. A first and second amplifier are connected at their supply terminals to the first and second switch. The first and second switches are operated to commutate the inductor between the amplifiers so as to provide an amplified signal while limiting the ripple voltage on the inductor and thus limiting the maximum voltage imposed across the amplifiers and switches.

Abstract: A high frequency amplifier comprising a first trans-impedance amplifier, a second trans-impedance amplifier, a third amplifier, and a variant current source is provided. The first trans-impedance amplifier receives an input current and outputs a first output voltage accordingly. The second trans-impedance outputs a second voltage. The third amplifier receives the first and the second voltage. The variant current source is connected between the input terminal of the second trans-impedance and a ground terminal or a power supply source. The variant current source delivers a variant current to change the second voltage such that the second voltage may follow the first voltage. The input current flows into the first trans-impedance amplifier, while the variant current flows into the second trans-impedance amplifier. The input current flows out the first trans-impedance amplifier, while the variant current flows out the second trans-impedance amplifier.

Abstract: There is provided a feedback amplifier capable of easily controlling its dynamic range without a separate gain control signal generation circuit. The feedback amplifier includes an input terminal detecting an input voltage from input current, a feedback amplification unit amplifying the input voltage to generate an output signal, and an output terminal outputting a signal amplified by the feedback amplification unit. The feedback amplification unit includes a feedback circuit unit including a feedback resistor located between the input terminal and the output terminal, and a feedback transistor connected in parallel to the feedback resistor; and a bias circuit unit supplying a predetermined bias voltage to the feedback transistor of the feedback circuit unit and merged in the feedback amplification unit.

Abstract: A lock detector receives a feedback signal from a phase-locked loop and a reference signal. The lock detector includes a first generator for receiving the reference and feedback signals, and for sampling the feedback signal with the reference signal. A second generator is coupled to the first generator for incrementing a count when the feedback signal is at different polarities at consecutive edges of the reference signal. An output line, for asserting a phase lock when the count reaches a defined value, is coupled to the second generator.

Abstract: A phase lock loop comprises a variable frequency oscillator (20), a divider (30), a phase comparator (40), a gain control stage (240), and a loop filter (50). The frequency response of the loop is measured by superimposing a modulation at a number of different rates on the error signal generated by the phase comparator, and by measuring for each modulation rate the peak-to-peak variation of the loop control signal controlling the oscillator frequency. If, due to errors in component values, the frequency response deviates from its desired value, the loop gain is adjusted to bring the frequency response close to its desired value.

Abstract: A voltage controlled oscillating means in a clock converter outputs a positive feedback signal for a positive feedback loop from one output terminal of buffer means forming a portion of a positive feedback loop using voltage controlled phase shifting means and outputs a PLL feedback signal from the other output terminal of the buffer means. The PLL feedback signal is fed back to phase detector means through a signal transmitting circuit. As a result, it is possible to form a PLL feedback loop, which is not affected by the load to thus output a stable clock signal of high frequency. Furthermore, it is possible to realize a small clock converter by narrowing the line width of a wiring pattern in the signal transmitting circuit.

Abstract: A surface-mounted oscillator configured by integrally accommodating an oscillation element, an IC chip, and a circuit element in a surface-mounted package is characterized in that the oscillation element, the IC chip, and the circuit element are arranged in positions in a direction vertical to a mounting surface of the surface-mounted oscillator. The oscillation element may be an oscillation element using bulk wave oscillation, or an oscillation element using surface wave oscillation.

Abstract: In a Wien-Robinson oscillator, a negative feedback path and a positive feedback path are arranged between the output of an operational amplifier and a reference ground potential. The negative feedback path contains two resistors which are connected in series and whose common circuit point is connected to the inverting input of the operational amplifier. The positive feedback path is formed from two RC elements which are connected in series and whose common circuit point is connected to the non-inverting input of the operational amplifier. If the aim is to keep the amplitude of the output voltage from the oscillator constant, additional measures are required, which increase the circuitry complexity. In order to stabilize the output voltage from the oscillator with little complexity, a third resistor is arranged between the output of the operational amplifier and that end of the positive feedback path which faces away from the reference ground potential.

Abstract: A cut of a piezoelectric resonator uses a quartz plate having an electric axis, mechanical axis, and optic axis on an X axis, Y axis, and Z axis, respectively. An X? axis is set by rotating the X axis with an angle of 3–30 degrees in a clockwise direction about the Z axis. A Z? axis is set by rotating the Z axis in the clockwise direction with an angle of 33–36 degrees about the X? axis. The quartz plate has sides parallel to the X? axis and Z? axis, respectively. Furthermore, the plate has sides parallel to X? axis and Z? axis, respectively, which have been rotated in the clockwise direction with angles of from ?35 degrees to ?2 degrees about a Y? axis that is the thickness direction of the cut of the piezoelectric resonator.

Abstract: MEMS-based, computer system, clock generation and oscillator circuits and LC-tank apparatus for use therein are provided and which are fabricated using a CMOS-compatible process. A micromachined inductor (L) and a pair of varactors (C) are developed in metal layers on a silicon substrate to realize the high quality factor LC-tank apparatus. This micromachined LC-tank apparatus is incorporated with CMOS transistor circuitry in order to realize a digital, tunable, low phase jitter, and low power clock, or time base, for synchronous integrated circuits. The synthesized clock signal can be divided down with digital circuitry from several GHz to tens of MHZ—a systemic approach that substantially improves stability as compared to the state of the art. Advanced circuit design techniques have been utilized to minimize power consumption and mitigate transistor flicker noise upconversion, thus enhancing clock stability.

Abstract: First and second calibration signals (308, 309) are sent to a frequency divider (102) and an adder (116) of a PLL section (100A), demodulated in a demodulator (111), filtered through a low pass filter (113) and a high pass filter (114) and thereafter sent to a modulation signal control circuit (115). The modulation signal control circuit (115) generates control information (318) in comparison with the phase and amplitude of the first and second calibration signals (308 and 309) and sends the control information (318) to a modulation control signal generator (106). Modulation control signal generator (106) holds the control information (318) and controls the values of the first modulation signal and second modulation signal sent to the frequency divider (102) and adder (116) on the based on the control information (318) held in modulation operation.

Abstract: A three-dimensional balun is disclosed by laminating alternate layers of conductor and dielectric substrate on top of each other to create a microwave circuit. The laminated layers are constructed in a transmission line configuration, corresponding to an equivalent circuit, wherein the first and third transmission lines, the fifth and seventh transmission lines, the second and fourth transmission lines, and the sixth and eighth transmission lines are pairs of coupling lines; one end of the sixth transmission line is defined as an input; one end of the seventh transmission line is defined as a first output; one end of the eighth transmission line is defined as a second output. When signals close to the center frequency of the operating balun are input from the unbalanced side, the signals are converted and then output through the first and second outputs having the same amplitude and producing 180-degree phase shifts.

Abstract: A transmission line for high-frequency differential signals and having a transforming impedance is formed into a substrate. The transmission line is comprised of a first slot, the opposing surfaces of which carry a conductive surface capable of carrying electrical signals. By virtue of their dimensions, spacing and dielectric filler, the conductive surfaces constitute a transmission line. A second slot, also with opposing surfaces, each of which also carry a conductive surface but which are spaced differently than the opposing surfaces of the first slot, provide a second transmission line but with a different impedance. The impedances between the two transmission lines are transformed by an impedance transition section of transmission line that is slot section the dimensions of which are tapered to meet the different slot dimensions of the two different transmission line segments.

Abstract: The invention discloses a new and original voltage variable resistor VVR with input and output ports and a first input and second input for control signals to set the impedance between the input and output ports as desired over a certain range and, thus, to optimize the operation of the VVR from the transmitter device control viewpoint as regards both the linearity and minimum impedance. The invention further discloses a method for controlling a VVR and a cellular radio system terminal.

Abstract: An inline phase shifter including a waveguide having a waveguide path and one of a micro-electromechanical device and a piezoelectric device positioned sufficiently adjacent to the waveguide for changing physical dimensions of the waveguide path upon actuation of the one device.

Abstract: A radio frequency (RF) filter includes a substrate, first and second dielectric layers formed on first and second portions of the substrate, a ground plane formed on a third portion of said substrate, a carbon nanotube array, and first and second electrodes. The third portion of the substrate includes, at least in part, the area between the first and second portions thereof. The carbon nanotube array is formed on a portion of said ground plane between the first and second dielectric layers. The first and second electrodes are formed on the first and second dielectric layers, such that an RF signal may be input to and output from the carbon nanotube array via the first and second signal guides. A third electrode is disposed over the carbon nanotube array and is used to voltage bias the array.

Abstract: A surface acoustic wave device for implementing an attenuation characteristic outside of the pass band and the narrow band characteristics, preferably for use as a filter. The surface acoustic wave device includes a piezoelectric substrate, interdigital transducers formed on the piezoelectric substrate, and first and second reflectors disposed on the sides of the interdigital transducers. Each of the first and second reflectors includes an open electrode block with a plurality of electrically independent electrode fingers, and a short electrode block with a plurality of electrode fingers of which both ends are electrically shorted.

Abstract: Systems and methods are taught for blocking the propagation of electromagnetic waves in parallel-plate waveguide (PPW) structures. Periodic arrays of resonant vias are used to create broadband high frequency stop bands in the PPW, while permitting DC and low frequency waves to propagate. Some embodiments of resonant via arrays are mechanically balanced, which promotes improved manufacturability. Important applications include electromagnetic noise reduction in layered electronic devices such as circuit boards, ceramic modules, and semiconductor chips.

Abstract: A 1:N MEM switch module comprises N MEM switches fabricated on a common substrate, each of which has input and output contacts and a movable contact which bridges the input and output contacts when the switch is actuated. The input contacts are connected to a common input node, and the output contacts are connected to respective output lines. Each output line has an associated inductance and effective capacitance, and is arranged such that its inductance is matched to its effective capacitance. The switches are preferably arranged symmetrically about the terminus point of the signal input line. A phase shifter employs at least two switch modules connected together with N transmission lines having different lengths, operated such that an input signal is routed via one of the transmission lines to effect a desired phase-shift.

Abstract: For manufacturing a thin electromagnetic relay having desired attractive force, both arms as upstanding portions disposed at both ends of a barrel of a plate magnetic material which is punched to be substantially U-shaped as viewed from the front by press working are bended to form magnetic poles having magnetic-pole surfaces extending in a horizontal direction. A vertical face passing through the center of the barrel crosses the centers of the magnetic-pole surfaces at right angles. The width of the barrel is smaller than the height of the barrel.

Abstract: An electromagnetic relay has an iron core having a protruding shaft and a magnetic pole portion. The protruding shaft is penetrated through a through hole provided on a metal case, and coil is wound around the protruding shaft. A voltage is applied to the coil for magnetization and stopped for demagnetization, hence to drive a contact mechanism with a movable iron piece that is attracted by and separated from the magnetic pole portion, thereby causing a reciprocating motion of the movable iron piece. The relay can prevent generation of eddy current.

Abstract: In the electromagnetic switching device, it is possible to miniaturize and have low costs, have quiet operation noise, and also quickly extinguish the arc. The electromagnetic switching device has an electromagnetic actuator with a movable iron core, a pair of fixed terminals that respectively have a fixed contact point, a movable contact that has movable contact points on the right and left ends, a shaft, and an enclosing component that holds the movable contact points and the fixed contact points. The pair of movable contact points respectively contact with and detach from the pair of fixed contact points, and the pair of fixed contact points respectively conduct each other and are insulated again through the shaft by moving the movable iron core along the axis using the electric magnetic actuator. A quasi-hermetically sealed space, which is the extinguishing space, is formed by the enclosing component and a first yoke.

Abstract: An electromagnetic contactor in which neighboring main contact points have an interphase barrier between them. A concave section is provided at the inner wall face of the interphase barrier at the middle of the emission path of the arc gas that is generated from the opening and closing of a main contact point. The concave section allows the arc gas passing from an arc generation point to an emission window to be accumulated in the concave section, which acts as a container, thus reducing the rate at which the arc gas is emitted. As a result, the amount of heat dispersed from the arc gas to the interphase barrier due to heat transfer is increased, thus reducing the temperature of the arc gas flowing from the emission window, which suppresses damage to the wiring cable that would otherwise occur due to excessive heating of the main terminal onto which the arc gas flows, and fusion of the interphase barrier.

Abstract: A ferrite core constituting a deflection yoke has a plurality of ridge-shaped convex portions on an inner circumferential surface. In a cross-section orthogonal to a center axis, the cross-sectional shape of an outer circumferential surface of the ferrite core is substantially circular, and the cross-sectional shape of an inner circumferential surface of the ferrite core excluding the convex portions is substantially circular in the vicinity of an end on a large diameter side of the ferrite core and is substantially rectangular in a portion between the vicinity of an end on a small diameter side and the vicinity of the end on the large diameter side. This can provide a low-cost color picture tube apparatus with a reduced deflection power and satisfactory productivity.

Abstract: The invention concerns a superconducting high-field magnet system (1) for a high-resolution magnetic resonance spectrometer, comprising a magnet coil (4) which is superconductingly short-circuited during operation, and generates a homogeneous temporally stable magnetic field during operation that meets the requirements for taking a high-resolution magnetic resonance spectrum. The magnet coil (4) comprises an LTS partial coil (4b, 4c) and an HTS partial coil (4a, 4d). The LTS partial coil (4b, 4c) can be separately short-circuited in a pure LTS circuit (14b) via an LTS switch (15b), and the HTS partial coil (4a, 4d) can be separately short-circuited in a pure HTS circuit (14) via an HTS switch (15a) and both partial coils (4a, 4d; 4b, 4c) are connected via an LTS-HTS joint (20) and are charged by the same power supply.

Abstract: A magnet structure for a Nuclear Magnetic Resonance imaging apparatus includes at least two opposing magnetic pole pieces, which are located at a certain distance from each other and delimit an imaging region. The pole pieces are formed by at least one massive layer of a magnetically permeable material, and at least one layer of magnetically permeable material having a pack of superimposed sheets or foils, electrically insulated from each other. Each of the sheets has cuts arranged over the surface of the sheet in positions that are at least partly non coincident with the cuts of at least one, or both adjacent sheets. The magnetically permeable sheets or foils have a first face and a second face and the cuts are so arranged on each sheet that the cuts of a sheet or foil are offset and not coincident with respect to the cuts of an adjacent sheet or foil, when said adjacent sheet is laid over the previous sheet in an overturned position, i.e.

Abstract: A choke coil according to the invention is configured to include: a coil incorporated with terminals and/or intermediate tap, the coil configured of a metal plate being punched and folded; a magnetic material buried with the coil therein; and a radiator of a material with excellent thermal conductivity disposed on a surface of the magnetic material. A small-sized, low-profile choke coil structurally stable with excellent heat dissipation is to be provided.

Abstract: To optimize the package dimensions of pencil-style ignition coils, a structural component including a primary wire and a primary bobbin is constructed in such manner that this structural component is also used as the encapsulation layer of the ignition coil.

Abstract: There is provided an inductive coupler for coupling a data signal to a phase line of a power line. The inductive coupler includes a split magnetic core having an aperture formed by an upper magnetic core and a lower magnetic core. The aperture permits the phase line to pass therethrough as a primary winding, the upper magnetic core is for making electrical contact with an outer surface of the phase line, and the lower magnetic core makes electrical contact with the upper magnetic core.

Abstract: The invention relates to an inductor comprising a plurality of interconnected conductive segments interwoven with a substrate. The inductance of the inductor is increased through the use of coatings and films of ferromagnetic materials such as magnetic metals, alloys, and oxides. The inductor is compatible with integrated circuit manufacturing techniques and eliminates the need in many systems and circuits for large off chip inductors. A sense and measurement coil, which is fabricated on the same substrate as the inductor, provides the capability to measure the magnetic field or flux produced by the inductor. This on chip measurement capability supplies information that permits circuit engineers to design and fabricate on chip inductors to very tight tolerances.

Abstract: A toroidal inductor, including a substrate (100), a toroidal core region (434) defined within the substrate, and a toroidal coil including a first plurality of turns formed about the toroidal core region and a second plurality of turns formed about the toroidal core region. The second plurality of turns can define a cross sectional area (440) greater than a cross sectional area (442) defined by the first plurality of turns. The substrate and the toroidal coil can be formed in a co-firing process to form an integral substrate structure with the toroidal coil at least partially embedded therein. The first and second plurality of turns can be disposed in alternating succession. The toroidal core region can be formed of a substrate material having a permeability greater than at least one other portion of the substrate.

Abstract: A mobile terminal for controlling a vehicle using a short message by establishing authentication information to establish mutual authentication between the vehicle acting and a mobile terminal. The mobile terminal requests initial information needed for an automatic control function from the vehicle using the authentication information, and checks the vehicle's automatic control available items associated with the initial information received from the vehicle. Upon receiving user's selection information needed for the automatic control function, the mobile terminal generates a short message containing a control command corresponding to items from among the checked automatic control available items, and transmits the short message to the vehicle. The user uses a short message in a mobile communication network to remotely control a vehicle. User interface using icons allow the user to conveniently control the vehicle at a remote site.

Abstract: A lock is operated by a lock controller that receives identifying signals transmitted from one or more wireless key devices. Weights are assigned to the identifying signals, and the lock is operated only if the weights of the received identifying signals satisfy a condition, such as a threshold condition applied to their sum. The weights are preferably assigned by counting the number of times each identifying signal is registered in the lock controller. The count may be kept in the lock controller or in the wireless key device itself.

Abstract: The present invention provides an electronic key system including an electrical/electronic key-like device and an electrical/electronic key receptacle capable of receiving a contactless type, contact type, or both types of key-like devices. The present invention further provides an electronic key system including an electrical/electronic key-like device and an intelligent electrical/electronic key receptacle wherein the system is capable of performing a transaction between the key-like device and the key receptacle after the key-like device is inserted into the key receptacle and moved to a predetermined position.

Abstract: An electronic circuit for a contactless tag includes a transceiving device having an antenna coil and a circuit changeover switch that switching between a state where the antenna coil forms a resonance circuit of the transceiving device and a state where the antenna coil forms a booster circuit.