644 results about "Parallel resonance" patented technology

An LC parallel resonance circuit is connected in series with the power supply side of the antenna conductor portion. The antenna conductor portion is configured so as to resonate at a frequency slightly lower than the center frequency in the higher frequency band of two frequency bands for transmitting and receiving radio waves. The LC parallel resonance circuit is configured so as to resonate substantially at the center frequency in the lower frequency band for transmitting and receiving a radio wave and be capable of providing to the antenna conductor portion a capacitance for causing the antenna conductor portion to resonate at the center frequency in the higher frequency band. Thus, a circuit for changing the upper and lower frequency bands is not needed. Such a change-over circuit, which is complicated, causes problems in that the conduction loss increases, and the antenna sensitivity deteriorates. Without need of the change-over circuit, the conduction loss can be reduced, the antenna sensitivity can be enhanced and costs can be reduced.

A collision prevention relational function is disclosed for RFID tags, which increases stability during system operations. The RFID tag includes a parallel resonance circuit having a coil, a resonance capacitor, an adjustment capacitor, a switching circuit, a rectification circuit, a smoothing capacitor, a constant-voltage circuit, a voltage detection circuit, an exclusive OR circuit, a timer circuit, a voltage detection circuit, a control circuit, an OR circuit, a latch circuit, an UID storage device, and a data modulator/demodulator. When a predetermined power supply voltage/operating voltage is obtained, an anti-collision algorithm identifies and adjusts RFID tags that experienced collision.

A filtering circuit with BAW type acoustic resonators having at least a first quadripole and a second quadripole connected in cascade, each quadripole having a branch series with a first acoustic resonator of type BAW and a branch parallel with each branch having an acoustic resonator of type BAW, the first acoustic resonator having a frequency of resonance series approximately equal to the frequency of parallel resonance of the second acoustic resonator, the branch parallel of the first quadripole having a first capacitance connected in series with the second resonator and, in parallel with the capacitance, a first switching transistor to short circuit the capacitance.

An antenna device comprising an antenna element disposed on a mounting board separate from a main circuit board, a coupling means disposed on the mounting board such that it is electromagnetically coupled to the antenna element, and a frequency-adjusting means disposed on the mounting board such that it is connected to the coupling means, the antenna element comprising first and second strip-shaped antenna elements integrally connected for sharing a feeding point, the second antenna element being shorter than the first antenna element; the coupling means being formed on a dielectric chip attached to the mounting board, and having a coupling electrode electromagnetically coupled to part of the first antenna element. The frequency-adjusting means comprises a parallel resonance circuit comprising a variable capacitance circuit and a first inductance element, and a second inductance element series-connected to the parallel resonance circuit.

A chip antenna 10 includes, inside a rectangular-parallelepiped base 11 having barium oxide, aluminum oxide, and silica as main constituents, a conductor 12 wound in a spiral form along the length direction of the base 11, and an LC parallel resonance circuit 13, which is inserted in the intermediate portion of the conductor 12 and which is connected electrically in series with the conductor 12, and includes, on the surface of the base 11, a power-feeding terminal 14 for applying a voltage to the conductor 12. The conductor 12 is separated into a first conductor 121 and a second conductor 122 by the LC parallel resonance circuit 13. The LC parallel resonance circuit 13 is formed of a coil L1, which is an inductance element, and a capacitor C1, which is a capacitance element, which are connected in parallel.

The invention discloses a high-voltage generator used for an X-ray machine and a control method thereof. The high-voltage generator comprises a rectifying and wave-filtering and soft-start unit connected with a power supply, a control power supply, and a voltage rising and rectifying unit in a high-voltage oil tank. The high-voltage generator is characterized in that the rectifying and wave-filtering and soft-start unit is connected with a power factor correction unit, is connected with the positive pole of an X-ray tube in the high-voltage oil tank through a high-voltage inverter and the voltage rising and rectifying unit, and is connected with the negative pole of the X-ray tube through a filament inverter and a filament converting circuit; a sampling circuit connected with a central control unit is arranged inside the high-voltage oil tank; and the central control unit is respectively connected with the high-voltage inverter, the filament inverter and a host computer. Compared with the prior art, the high-voltage generator has the advantages that the high-voltage generator adopts a series-parallel resonance technique to realize the zero-voltage opening of a switch tube, and thus the switching frequency can be improved to 100 kHz; the problems of high voltage insulation and protection caused by extracting a high voltage wire externally connected with an X-ray tube from the high-voltage oil tank are avoided because that the X-ray tube is integrated inside the high-voltage oil tank.

An automatic temperature compensated real-time clock (RTC) chip includes a clock portion having a crystal oscillator block including crystal compensation circuitry adapted to be coupled to a crystal. The crystal compensation circuitry includes a non-linear capacitor DAC including a plurality of load capacitors, wherein the load capacitors have respective switches which switch respective ones of the load capacitors to change a parallel resonance frequency (fp) generated by the oscillator block. The capacitor DAC is arranged so that Analog Trimming (ATR) bits received cause an arrangement of the switches to provide a non-linear change in overall load capacitance to result in a linear relationship between fp and the ATR bits. A temperature sensor block is coupled to the crystal for measuring a temperature of at least the crystal. An A/D converter is coupled to the temperature sensor for outputting a digital temperature signal representative of the temperature of the crystal. A DSP engine receives the digital temperature signal and calculates frequency correction needed to correct for frequency inaccuracy and determines a bit sequence including the ATR bits appropriate to achieve the frequency correction.

An RF coil has at least one conductor loop and a parallel circuit provided with a first branch and a second branch is installed. The first branch has a first capacitor and the second branch has a third capacitor and a first parallel resonance circuit configured by a second capacitor and a first inductor. The first capacitor has capacity to allow the RF coil to resonate at the time of transmission/reception of the first resonance frequency signal corresponding to an element with a higher magnetic resonance frequency, and capacity of the second capacitor and a value of the first inductor are determined as an accumulated value thereof based on the first resonance frequency. The third capacitor has capacity to allow the RF coil to resonate at the time of transmission/reception of the second resonance frequency signal corresponding to an element with a lower magnetic resonance frequency.

Disclosed is a plasma process apparatus in which a semiconductor device manufacturing process using a plasma is performed. The apparatus includes: a vacuum chamber in which a semiconductor device manufacturing process is performed; a very high frequency (VHF) power source for generating a VHF power; a VHF parallel resonance antenna having a plurality of antenna coils connected in parallel to each other, and multiple variable capacitors insertion-installed in series in the antenna coils, the antenna being installed at an outer upper portion of the vacuum chamber, and supplied with the VHF power from the VHF power source; and an impedance matching box for impedance matching between the VHF power and the VHF parallel resonance antenna. Preferably, the variable capacitor is a coaxial capacitor including: a first insulator tube; first two metal tubes respectively extending from both ends of the first insulator tube; a second insulator tube surrounding the first insulator tube, and partially surrounding the first two metal tubes placed adjacent to both sides thereof; and a second metal tube surrounding the second insulator tube, and installed so as to glide along an outer side surface of the second insulator tube.

A wireless device (100) includes a first circuit board (102), a second circuit board (104), and a distributed load (106) having an inductive coupling (112) and a capacitive coupling (114). The inductive coupling (112) and the capacitive coupling (114) form a parallel resonance at predefined frequencies of interest. The second circuit board (104) includes an antenna (116) for receiving and transmitting radio waves.

A power amplifier comprises a power amplification stage and an impedance transformation stage. The power amplification stage is connected with the impedance transformation stage in series. A differential cascade circuit structure is adopted in the power amplification stage, and the impedance transformation stage is formed by connecting a three-level parallel resonance network, a fundamental wave resonance network and an L-type impedance transformation network in series. The power amplifier has a linear configurable mode and a non-linear configurable mode, the working frequency range covers 0.1GHz to 1.5 GHz and optimization of linearity and efficiency can be realized through flexible configuration under different scenes.

The invention relates to an L wave band miniature band pass filter with low loss and high suppression, which comprises a surface-mounted input/output interface, five parallel resonance units achieved by adopting three layers of folded and coupled strip lines, four zero setting circuits and an input and output inductor, which are all achieved by adopting a multi-layer low temperature co-fired ceramic technology. The invention has the advantages of small volume, light weight, high reliability, excellent electrical performance, good phase-frequency characteristic linearity, good temperature stability, good bulk electrical performance consistency, low cost, mass production and the like, and is particularly suitable for radar, communication, rocket-bearing, airplane-bearing, missile-bearing, spacecrafts, one-man mobile communication terminals and other handheld and portable radio communication terminal products, as well as corresponding band systems which are serious about volume, weight, electrical performance and the like.

The present invention provides a multilayered chip capacitor (MLCC) comprising internal electrodes and external electrodes formed to be perpendicular to the internal electrodes, whereby parasitic capacitance is reduced, resulting in no parallel resonance frequency effects. In addition, the MLCC has a capacitor structure, which provides a first surface and a second surface formed in a stacking direction of the dielectric layers in the capacitor body as a top surface and a bottom surface. Hence, in the thin capacitors having the same size, the number of internal electrode layers is increased, thereby reducing the ESR and ESL. Further, the PCB having an embedded MLCC is easily manufactured.

Disclosed herein is a clock supplying apparatus for supplying a clock to a digital circuit, including: a differential clock driver; a first clock line along which a first clock of a positive phase from the clock driver propagates; a second clock line along which a second clock of a reverse phase from the clock driver propagates; and a parallel resonance circuit of an inductor and a capacitor. The inductor of the parallel resonance circuit is connected at a first end to the first clock line and at a second end to the second clock line. The capacitor of the parallel resonance circuit is connected at a first electrode to the first clock line and at a second electrode to the second clock line.

Provided is a power supply system which makes it possible to stably supply power regardless of changes in placement of electrodes. The power supply system for supplying power to a load (24). The fixed body (10) includes: a first power-transmitting electrode (12) and second power-transmitting electrode (13); and an AC power supply (11) to supply AC power to the first power-transmitting electrode (12) and second power-transmitting electrode (13). The movable body (20) includes: a first power-receiving electrode (21a) and second power-receiving electrode (21b) to form a first coupling capacitor (30) and a second coupling capacitor (31), respectively, by being placed in a manner opposed to and not contacting corresponding ones of the first power-transmitting electrode (12) and second power-transmitting electrode (13) while facing one side of an interface, the one side not being faced by these power-transmitting electrodes, and a first capacitor (22a) and first coil (22b) connected to one another in parallel between the first power-receiving electrode (21a) and second power-receiving electrode (21b). The AC power supply (11) transmits power to the load (24) via the first and second coupling capacitors under a condition that causes parallel resonance between the first capacitor (22a) and first coil (22b).

The invention discloses a circuit structure which utilizes an adjustable inductor and improves linearity of a power amplifier as well as a method. The circuit structure contains an on-chip transformercoupling input network, a transistor amplifier circuit, an output network, a control and bias generating circuit and an envelope detection circuit; the transistor amplifier circuit is respectively connected with the on-chip transformer coupling input network and the output network; the transistor amplifier circuit is provided with a capacitor-inductor parallel resonance loop as well as a capacitor and the adjustable inductor connected in parallel in the capacitor-inductor parallel resonance loop; and the envelope detection circuit is connected with the control and bias generating circuit, detects an envelope signal of a radio frequency signal of the input network or output network and generates the required bias signal and a control signal for the adjustable inductor. The circuit structure disclosed by the invention realizes dynamic and adjustable low-resistance bias loop by adopting a parallel adjustable LC loop way, AM-AM nonlinearity is improved, and the adjustable inductor eliminates AM-PM nonlinearity; and the circuit structure can be conveniently used in an inter-stage matching and impedance transformer network of a multistage amplifier, and cascade connection of a multistage radio frequency power amplifier can be realized conveniently.

The invention discloses a circuit and a method for measuring stray inductance of a current conversion circuit of a three-level converter. The circuit comprises a first IGBT (insulated gate bipolar transistor), a second IGBT, a third IGBT, a fourth IBGT, a first clamp diode, a second clamp diode, a first resonant capacitor, a second resonant capacitor, a first direct-current support capacitor, a second direct-current support capacitor, a laminated busbar, a direct-current power supply and a freewheel reactor. The method includes forming different freewheel circuits by the freewheel reactor; exerting double pulses to each corresponding IGBT; taking an average value of resonance current frequencies at a turn-on moment and a turn-off moment; and precisely computing the stray inductance of the current conversion circuit by an LC parallel resonance characteristic realized by the resonant capacitors and the stray inductance of the circuit. The circuit and the method have the advantages that actual operation is facilitated, the stray inductance of the current conversion circuit of the three-level converter can be accurately measured, overvoltage levels of a power device under different current grades of the three-level converter can be accurately controlled conveniently, and accordingly establishment of a system control strategy can be guided.

A parallel resonance frequency can be adjusted in order to stably and securely block different high frequency noises flowing into a line such as a power feed line or a signal line from electric members including a high frequency electrode within a processing chamber. A filter 102(1) coaxially accommodates a coil 104(1) within a cylindrical outer conductor 110, and a ring member 122 is coaxially installed between the coil 104(1) and the outer conductor 110. The ring-shaped member 122 may be a plate body of a circular ring shape on a plane orthogonal to an axial direction of the outer conductor 110 and made of a conductor such as cupper or aluminum and electrically connected with the outer conductor 110 while electrically insulated from the coil 104(1).

First base layers made of TiN or TiO_xN_y (where, 0<x<0.2, x+y=1) and second base layers made of Cr are provided between interdigital transducer portions and a piezoelectric substrate, and accordingly, it is possible to prevent voids from being generated in the interdigital transducer portions, which improves a power resistance of the surface acoustic wave device. In addition, since it is possible to prevent the voids from being generated in the interdigital transducer portions, it is possible to suppress the resistance of the interdigital transducer portions from increasing, which can reduce the loss of power. In addition, it is also possible to reduce the variations in a serial resonance frequency and a parallel resonance frequency.

The invention relates to a 6.8-kilomegahertz miniature filter with low loss, high stop band and multi-zero suppression, which comprises an input port, an output port, three parallel resonance units, two zero setting units, and the like, which are achieved by adopting a multi-layer low temperature co-fired ceramic technology, wherein an input inductor and an output inductor are designed by distributed parameter strip lines; a first inter-stage inductor and a second inter-stage inductor adopt space coupling and distributed parameter inductors; a first inter-stage capacitor and a second inter-stage capacitor adopt space coupling and distributed parameter capacitors; a first coupling capacitor is a medium flat Z-shaped capacitor; the three parallel resonance units are designed by two layers of folded and coupled strip lines, and one end of each layer of strip line is hung in air, and the other end is grounded. The invention has the advantages of small volume, light weight, high reliability, good temperature performance stability, excellent electrical performance, high yield, low cost and good bulk electrical performance consistency.