119 results about "Resonant filter" patented technology

A piezoelectric resonant filter includes a group of series resonators and a group of parallel resonators for forming a ladder-type filter circuit. Each of the resonators has a piezoelectric thin film having piezoelectric characteristic, and lower and upper electrodes disposed on opposite surfaces of the piezoelectric thin film for applying an excitation voltage to the piezoelectric thin film. The group of the parallel resonators exhibits a low frequency side attenuation extremum in the filter whereas the group of the series resonators exhibits a high frequency side attenuation extremum in the filter. At least one of the group of the series resonators and the group of the parallel resonators has a temperature compensating layer for bringing the temperature coefficient of the resonant frequency close to zero.

Methods and compositions are provided for detecting biomolecular interactions. The use of labels is not required and the methods can be performed in a high-throughput manner. The invention also provides optical devices useful as narrow band filters.

A high intensity discharge (HID) lamp driving circuit. The HID lamp driving circuit includes a first pair of switching devices connected to a high frequency resonant filter, and a second pair of switching devices connected to a ripple reducing filter. A HID lamp is connected between the first pair of switching devices and second pair of switching devices, with a dc power supply being connected to the first pair of switching devices and the second pair of switching devices. The first pair of switching devices and the second pair of switching devices are connected to a common ground with the dc power supply. The lamp driving circuit operates in a half bridge topology during a start-up operation mode of the lamp, and operates in a full-bridge topology during a steady-state operation mode of the lamp. The HID lamp driving circuit is operated in an active zero current switching scheme.

Methods and compositions are provided for detecting biomolecular interactions. The use of labels is not required and the methods can be performed in a high-throughput manner. The invention also provides optical devices useful as narrow band filters.

Performing high-resolution determination of the relative shift of the spectral properties of a biosensor. The shift in the resonance peak of the biosensor is indicative of the amount of material bound to the surface of the biosensor. A preferred biosensor is a Guided Mode Resonant Filter Biosensor (GMRFB). In one aspect of the invention, curve fitting is used to determine the relative location of the spectrum of the unexposed biosensor with respect to those spectra that are altered (e.g., shifted) by the presence of materials bound to the surface of the biosensor. In an alternative embodiment, the cross correlation function is used to detect spectral peak offsets between a reference spectrum and a spectrum measured from an exposed biosensor. In yet another alternative, maximal likelihood estimation techniques are used to determine the spectral shift or offs.

PCT No. PCT / HU95 / 00049 Sec. 371 Date Apr. 2, 1998 Sec. 102(e) Date Apr. 2, 1998 PCT Filed Oct. 3, 1995 PCT Pub. No. WO97 / 13391 PCT Pub. Date Apr. 10, 1997A high-frequency filtered dimmable electronic ballast circuit for powering low-pressure fluorescent lamps includes an input protection device; a radio-frequency filter connected to an output of the input protection device; a rectifier connected to an output of the radio-frequency filter; a power factor correcting switching power supply device connected to an output of the rectifier; a current controlled push-pull converter connected to an output of the switching power supply device; a series-parallel resonant filter composed of a capacitor in series with two inductors having a common connection in parallel with an additional capacitor connected to an output of the push-pull converter to maintain voltage wave forms essentially sinusoidal and of constant amplitude regardless of loading; a fluorescent lamp connected to an output of the resonant filter; and an external on / off switching circuit connected directly or by an optical or magnetic insulation device to an input of the push-pull converter for renotely turning on and off the fluorescent lamp.

A piezoelectric resonant filter includes a group of series resonators and a group of parallel resonators for forming a ladder-type filter circuit. Each of the resonators has a piezoelectric thin film 15 having piezoelectric characteristic, and lower and upper electrodes 14 and 16 disposed on opposite surfaces of the piezoelectric thin film 15 for applying an excitation voltage to the piezoelectric thin film 15. The group of the parallel resonators exhibits a low frequency side attenuation extremum in the filter whereas the group of the series resonators exhibits a high frequency side attenuation extremum in the filter. At least one of the group of the series resonators and the group of the parallel resonators has a temperature compensating layer 20 for bringing the temperature coefficient of the resonant frequency close to zero. The thickness of the temperature compensating layer 20 in the group of the series resonators is different from the thickness of the temperature compensating layer 20 in the group of the parallel resonators.

The invention discloses a low-frequency PWM rectifier and compensation capacitor based wireless charging apparatus. The wireless charging apparatus comprises a rectifying circuit, a filtering voltage-stabilizing capacitor, an inversion power switch, a launching circuit resonant capacitor, a hall current sensor, a launching circuit resonant coil, a receiving circuit resonant coil, a compensation capacitor, a rectifying power switch, a resonant filtering capacitor, a resonant filtering inductor, a load resistor, a high frequency inversion driving circuit, a microprocessor, an analog-digital converter, a hall voltage sensor, a signal detection conditioning circuit and a PWM rectifier driving circuit. According to the wireless charging apparatus, the resonance of the launching circuit and the receiving circuit is realized; the direct current voltage output range of the charging apparatus can be adjusted by the compensation capacitor; meanwhile, the operating frequency and loss of the power switch device are greatly lowered; the operating frequency section of the system is expanded; and the design flexibility of the resonant coil is improved as well.

An MRI compatible electrode circuit construct is provided. The construct includes at least two filter components constructed from an electrode wire. One filter component may be a resonant LC filter at or near an electrode / wire interface that resolves the issue of insufficient attenuation by effectively blocking the RF induced current on the wire from exiting the wire through the electrode. The second filter component may include one or more non-resonant filter(s) positioned along the length of the electrode wire that resolve(s) the issue of excessive heating of the resonant LC filter by significantly attenuating the current induced on the wire before it reaches the resonant LC filter. The non-resonant filter(s) may also attenuate the RF current reflected from the resonant LC filter thereby resolving the issue of the strong reflected power from the resonant filter and the associated dielectric heating.

The invention discloses a magnetic coupling resonant wireless electric energy transmission device based on a low frequency PWM rectifier. The device comprises a rectifier, a voltage stabilizing capacitor, an inverter power switch, an emission circuit resonant capacitor, an emission circuit resonant coil, an emission circuit current sampling resistor, a receiving circuit resonant coil, a receiving circuit current sampling resistor, a rectifier power switch, a resonant filter capacitor, a resonant filter inductor, a load resistor, a transmitting end signal conditioning circuit, a transmitting end analog to digital converter, a transmitting end microprocessor, a transmitting end high frequency inverter driving circuit, an induction voltage detection coil, a receiving end signal conditioning circuit, a receiving end analog to digital converter, a receiving end microprocessor and a PWM rectifier driving circuit. According to the device, the resonance of an emission loop is ensured, the tracking of transmitting end working frequency, the resonance of a receiving circuit and the constant output of load voltage are realized, the requirement of working frequency by a power switch device is greatly reduced, and a space is provided for the device to raise power supply working frequency.

The invention relates to a switchable filter group of surface acoustic wave having two channel bandwidths, which comprises a multi-fling switch, a controller and a plurality of filters of surface acoustic wave and is characterized in that: a plurality of filters of surface acoustic wave form at least a narrow-band channel and a wide-band channel; the narrow-band channel comprises two concatenated filters of surface acoustic waves which both apply unidirectional transducer structures of single-phase made on quartz; the wide-band channel comprises two concatenated different filters of surface acoustic wave, wherein, a pre-stage filter of surface acoustic wave applies a vertical coupling structure of a resonate filter, and a last-stage filter of surface acoustic wave applies a structure of a sector filter. The invention can realize low insertion loss in the narrow-band channel and also realize low rectangle coefficient; at the same time, the invention can realize low insertion loss in the wide-band channel, high stopband rejection and low rectangle coefficient, and the insertion loss and the narrow-band channel are close to passing.

The invention discloses a wireless charging device of small-sized electronic equipment, which mainly comprises an emission device and a receiving device, wherein the emission device comprises an external crystal oscillator, a frequency divider, a D-type power amplifier driving chip or a mutual inductance coupler, a D-type power amplifier module, a resonant filter circuit, an emission coil, a level switching module, a level detecting module, a control module, an indicator lamp and a buzzer; and the receiving device comprises a receiving coil, a receiving-end impedance matching network, a rectification filter module and a voltage stabilizing module. The wireless charging device provided by the invention can be applied to carrying out wireless charging on all low-power (5 W or less) electronic equipment including mobile phones, MP3 (Moving Picture Experts Group Audio Layer-3) players, MP4 (Moving Picture Experts Group Audio Layer-4) players, cameras and the like, thereby realizing that certain voltage and power are supplied to charge or supply power in a distance range meeting a design requirement. The wireless charging device of the small-sized electronic equipment has the advantages of simple structure, wide application, capability of efficiently charging in a certain distance, safety and no radiation, and the like.

The invention discloses a multistage radio frequency power amplifier circuit capable of reducing interference on an ISM frequency band. One or a plurality of resonant filter matching networks are arranged among stages of a multistage radio frequency power amplifier, the resonant filter matching networks enable power of succeeding impedance of the radio frequency power amplifier matched with a front power amplification tube to output a load value and simultaneously are applied to inductance and capacitance (LC) resonant network resonance to ISM frequency band frequency and / or offset frequency of radio frequency band and the ISM frequency band. The multistage radio frequency power amplifier circuit capable of reducing the interference on the ISM frequency band enables the multistage radio frequency power amplifier to effectively reduce the interference on the ISM frequency band without reducing overall efficiency and solves coexisting problems of radio frequency signals and ISM frequency band signals.

A circuit includes a first filter comprising a first inductor coupled to a first variable capacitor, wherein the first filter is associated with a first resonant frequency. The circuit further comprises an amplifier coupled to the first filter and a second filter coupled to the amplifier. The second filter comprises a second inductor coupled to a second variable capacitor, wherein the second filter is associated with a second resonant frequency that is substantially the same as the first resonant frequency. At least a portion of the first filter and at least a portion of the second filter are formed on an integrated circuit.

The invention discloses a tunable three-ring cascade filter. The tunable three-ring cascade filter comprises an input waveguide (10) which is the input waveguide of a first-level micro-ring resonant cavity filter (20), the first-level micro-ring resonant cavity filter (20) which is coupled with the input waveguide in the same plane, a second-level micro-ring resonant filter (21) which is coupled with the first-level micro-ring resonant cavity filter in the same plane, a third-level micro-ring resonant cavity filter (22) which is coupled with the second-level micro-ring resonant cavity filter in the same plane, a single-mode output waveguide (11) which is the output waveguide of the third-level micro-ring resonant cavity filter (22), and a heater (30) which is used for heating the first-level micro-ring resonant cavity filter, the second-level micro-ring resonant cavity filter and the third-level micro-ring resonant cavity filter, wherein the radius of the third-level micro-ring resonance cavity filter (22) is equal to the radius of the first-level micro-ring resonant filter.

A novel flat-wire-pair cable and resonant filter termination employing active interconnect principles is disclosed. The invention implements flattened conducting wires coated with insulation that are bonded to each other, providing approximately rectangular cross-sections and flat surfaces for the transport of charge through the wires. The flat wire pair may then be twisted for additional cross-talk minimization, with the twist occurring simultaneously and in identical fashion on both wires due to their attached arrangement. The terminating ends of the cable are routed on an insulating substrate forming a connector body, with the traces ending in conducting structures providing a matched resonating filter function. This filter is tuned to provide maximal benefit for the highest significant spectral content in transmitted signals. Through these enhancements, the invention interconnect architecture substantially reduces signal loss due to skin-effect and eliminates intra-pair skew. Through its active interconnect design, it amplifies high-frequency content and recovers signal energy lost due to attenuation through the length of the cable and connector termination.

A solid state image sensor includes a plurality of pixels, each having a photoelectric conversion section formed in the inside of a substrate and a light-receiving section formed on the side of a light-receiving surface of the substrate. At least a part of the plurality of pixels is ranging pixels. The light-receiving section of each of the ranging pixels is equipped with a guided mode resonant filter adapted to reflect incident light getting into the inside of the light-receiving section at a specific incident angle. The normal line of the guided mode resonant filter is inclined relative to the principal ray of the flux of light entering the guided mode resonant filter.

The invention proposes a DC multi-input single-output resonant converter and a control method thereof, and relates to the field of a resonant filter. The DC multi-input single-output resonant converter comprises one or more parallel resonant conversion coupling pairs and an output filter circuit, wherein each parallel resonant conversion coupling pair is connected in series with the output filter circuit and comprises two resonant conversion circuits, each resonant conversion circuit comprises a resonant circuit and a rectification circuit, the resonant circuits and the rectification circuits in each resonant conversion coupling pair are coupled by a transformer, and the two resonant circuits in each resonant conversion coupling pair are coupled by an inductor. By the DC multi-input single-output resonant converter, less magnetic devices are used, and the purposes of reducing the numbers of the magnetic devices, reducing the device volume and improving the power density can be achieved.

The supply circuit for the electrodes comprises a series resonant filter and a parallel resonant filter, synthonised to admit the fundamental signal of the input signal and simultaneously and exponentially attenuate the remaining harmonics by increasing the frequency thereof, in such a way that the input signal with harmonics only passes the fundamental signal without attenuation to the output, while the harmonics causing interferences are increasingly attenuated as their frequency is raised.

A nondestructive evaluation apparatus and method for qualifying cold worked fastener holes. In an illustrative embodiment, the apparatus comprises a probe and a detector that interprets probe signals. An inductive sensor coil located in the probe uses a magnetic shielding arrangement to focus sensing to a specific zone of cold worked material around a hole in a test specimen. The shielding mitigates edge effects around the hole and measurement dilution away from the hole. A reference coil, located on not cold worked material away from the hole, provides a comparative baseline measurement. Sensor coils are arranged in a novel resonant filter bridge circuit in the probe and connected to the detector. The detector evaluates impedance changes on the probe caused electrical conductivity variations in the test specimen and correlates the changes to cold work quality.

The invention discloses a multilayer-film filling type composite medium nanometer period grating structure and a manufacturing method of the multilayer-film filling type composite medium nanometer period grating structure. The multilayer-film filling type composite medium nanometer period grating structure is composed of a one-dimensional periodicity multi-layer film structure formed by medium gratings in a compounded mode, the duty ratio of the medium gratings is 1:1, and the period of the medium gratings is 100 nanometers to 1 micrometer. Medium materials with the refraction index different from the refraction index of the medium gratings and the heights same as the heights of the medium gratings are deposited at the positions of gaps of the concave portions of the medium gratings, and the multi-layer film structure is composed of two different kinds of medium materials in an alternative mode. The manufacturing method includes the main steps that (1) an ion beam assists an electron beam evaporating coating technology to manufacture a periodicity multi-layer film photonic crystal on the substrate, and (2) the nanometer coining technology, the reaction ion etching process and the electron beam evaporation coating and lifting-away technology are used for manufacturing the one-dimensional filling type composite medium on the medium multilayer films. The manufacturing method of the multiplayer-film filling type composite medium nanometer period grating structure is convenient to use and reliable. According to the filling type composite medium nanometer period grating structure, spectrum sidebands can be effectively restrained, the transmissivity or the reflection rate of a mode guiding resonant filter is improved, and the performance of the mode guiding resonance filter is improved.

The invention belongs to the technical field of signal filtering and provides an intelligent-tracking tunable band-pass filtering device which consists of a central processing unit, first, second, third and fourth DA converters, an RAM, an external data interruption and high-pass filter, a first band-stop resonance filter, a second band-stop resonance filter, a low-pass filter, an n-shaped resistance impedance matching device, as well as a first and a second single-chip integrated radio-frequency amplifier. The intelligent-tracking tunable band-pass filtering device adopts the high-pass filter with unchanged cut-off frequency to inhibit static stray signals (wherein the frequency and the power are unchanged), and adopts two band-stop resonance filters with changeable resonance frequency and one intelligent-tracking low-pass filter to constitute an intelligent-tracking filtering device which has changeable central frequency and changeable relative bandwidth to inhibit the static stray signals.

A DC-DC converter circuit includes a transformer with a resonate filter or snubber connected at a primary side and a switch for controlling operation of the converter. A secondary side of the transformer includes self-driven synchronous rectifiers and an output filter. Transistors are provided at the gates leads of the rectifiers and themselves are provided with a fixed voltage at their gates so as to clamp the peak voltages across to the rectifiers.

A tubular resonant filter comprises a multilayer sheet in a rolled configuration comprising multiple turns about a longitudinal axis, where the multilayer sheet includes a strain-relieved layer, a patterned first conductive layer on the strain-relieved layer, an insulating layer on the patterned first conductive layer, and a patterned second conductive layer on the insulating layer and the patterned first conductive layer. The patterned first and second conductive layers and the insulating layer are interrelated to form a rolled-up inductor connected to a rolled-up capacitor on the strain-relieved layer.

A medical probe includes a flexible insertion tube having a distal end for insertion into a body cavity and having a proximal end. The probe further includes an electrode attached to the distal end of the insertion tube and configured to make electrical contact with tissue in the body cavity. An electrical lead runs through the insertion tube between the distal and proximal ends. In addition a coil is electrically coupled between the electrode and the lead in the insertion tube so as to define a resonant circuit having a resonant frequency in a range between 1 MHz and 300 MHz.