478 results about "Impedance Converter" patented technology

A living body measuring sensor (1) is made to contact a body surface of a measuring subject through capacitance coupling using a cloth (6) between a metal electrode (2) and the body surface as the capacitance, a living body electric signal is extracted from the metal electrode (2), and an elctrocardiographic waveform is outputted based on an output of the living body measuring sensor (1) using an impedance converter having a high input impedance and a low output impedance.

The invention relates to a device in an electromagnetic measurement while drilling system for receiving an electromagnetic signal with measurement data information sent underground on the ground and transmitting the signal to a data processing computer, and a method thereof. The device uses two antennas in a well field to receive an electromagnetic signal sent underground and a well field noise signal respectively; and the two signals enter a program controlled low noise preamplifier to be amplified through the coupling of an impedance converter, then enter a signal conditioning module for processing, and then enter a digital signal processing module through analog-to-digital conversion, and finally data is transmitted to a computer terminal through an interface module. The device is matched with a downhole electromagnetic signal transmitter to form the electromagnetic measurement while drilling system to form the information communication between underground and ground. The electromagnetic measurement while drilling system is not affected by drilling fluid medium, can perform data transmission without circulating a drilling fluid under any working condition, and can solve the measurement while drilling problem in gas drilling and aerated drilling.

In accordance with an embodiment, a system for amplifying a signal provided by a capacitive signal source includes an impedance converter having an input node configured to be coupled to a first terminal of the capacitive signal source, and an adjustable capacitive network having a first node configured to be coupled to a second terminal of the capacitive signal source and a second node coupled to an output node of the impedance converter.

The invention discloses a welding quality monitoring system which comprises a signal acquiring module, a signal conditioning module, a microcontroller and transceiver module and an upper computer. The signal acquiring module is arranged in a welding machine and acquires signals to be detected during welding, the signal conditioning module is connected with the signal acquiring module, the microcontroller and transceiver module are connected with the signal acquiring module, and the upper computer is connected with the microcontroller and transceiver module. The welding quality monitoring system can utilize a signal acquiring circuit and a PIC (positive-impedance converter) single-chip microcomputer to monitor and store intrinsic electric parameter signals in real time during welding, communicate with the upper computer and realize network-based management.

The invention relates to a signal transmitting device for realizing wireless measurement while drilling. A downhole signal transmitting device for an electromagnetic measurement while drilling system comprises an upper drilling string and a lower drilling string, and an insulating joint is contained between the upper drilling string and the lower drilling string; and the upper drilling string and the lower drilling string are used for forming an asymmetric dipole antenna. The transmitting device adopts software radio technology to realize various functions of wireless transmission; the impedance matching between a transmitter antenna and transmission medium is realized through an impedance converter; and the dipole antenna is adopted to transmit a measurement while drilling data signal. The device and the method improve the adaptive capacity and measurement depth of the electromagnetic measurement while drilling system to different strata.

An electrostatic capacitance detection circuit 10 comprises an AC voltage generator 11, an operational amplifier 14 of which non-inverting input terminal is connected to specific potential (a ground in this example), an impedance converter 16, a resistance (R1) 12 connected between the AC voltage generator 11 and an inverting input terminal of the operational amplifier 14, a resistance (R2) 13 connected between the inverting input terminal of the operational amplifier 14 and an output terminal of the impedance converter 16, and an impedance element (a capacitor) 15 connected between an output terminal of the operational amplifier 14 and an input terminal of the impedance converter 16, and a capacitor to be detected 17 is connected between the input terminal of the impedance converter 16 and specific potential. The electrostatic capacitance detection circuit 10 and the capacitor 17 are located adjacently.

The invention provides a method for widening the bandwidth of a Doherty power amplifier and the Doherty power amplifier improved with the method. The Doherty power amplifier comprises a bandwidth power distributor module, a bandwidth input matching network module, a main power amplifier, a peak value power amplifier, a bandwidth output matching network module, a compensation line module and an impedance converter module, wherein the compensation line module comprises a compensation line of a main power amplifier branch and a compensation line of the peak value power amplifier branch, the compensation line of the main power amplifier branch converts load impedance into an optimal load impedance point in a lower power state; the compensation line of the peak value power amplifier branch enables the output impendence of the peak value power amplifier to present infinity and prevents the power of the main amplifier from being leaked to the peak value power amplification branch in a low power state. According to the invention, the bandwidth of the Doherty power amplifier can be widened and the returning efficiency of the Doherty power amplifier can be improved, load conditioning can be better achieved, the Doherty power amplifier can be applied to a multi-module base station and software radio, and energy conservation and cost reduction are facilitated.

An image sensing apparatus comprises a transfer block including a first transfer unit and a second transfer unit, wherein the first transfer unit includes a first impedance converter which transfers a first signal to the output unit, and the first transfer unit transfers, as a third signal, a difference signal between a first offset of the first impedance converter and a signal obtained by superimposing the first offset on the first signal, the second transfer unit includes a second impedance converter which transfers a second signal to the output unit, and the second transfer unit transfers, as a fourth signal, a difference signal between a second offset of the second impedance converter and a signal obtained by superimposing the second offset on the second signal, and the output unit calculates a difference between the third signal and the fourth signal, generating and outputting an image signal.

A soil moisture wireless measuring device comprises two parts, namely a wireless sensing device and a wireless setting device which is connected with the wireless sensing device and is used for detection operation. The wireless sensing device which is used to measure soil water content, soil temperature and soil compactness comprises an impedance converter, a pressure sensor, a temperature sensor, an information acquisition device, a second wireless communication module and a CPU processor. The wireless setting device which is designed as a hand held type instrument comprises a central controller, and a keyboard input module, a display module, a memory module and a first wireless communication module respectively connected with the central controller. The impedance converter consists of three parts, namely a signal source, a transmission line and a probe. The soil moisture wireless measuring device provided by the invention has the advantages that: the device is capable of measuring the soil temperature, soil compactness and soil water content simultaneously; the device has the performances of high bandwidth, high linearity and low power consumption; the device facilitates the realization of the real-time detection of field soil water content with brief design, simple operation and portability.

The invention discloses a structure for detecting the vibration displacement of a loudspeaker. The structure comprises a vibration system provided with a movable pole plate, a magnetic circuit system and a fixed pole plate, wherein the fixed pole plate is arranged below the vibration system and is opposite to the movable pole plate, and the movable pole plate and the fixed pole plate form a capacitor. The invention further discloses a double-effect device capable of realizing acoustic-electric inter-conversion. The double-effect device further comprises an impedance converter connected with the capacitor, wherein the impedance converter comprises a field-effect transistor and a diode. The movable pole plate of the capacitor is arranged on the vibration system, the fixed pole plate is arranged below the vibration system and fixed, and the actual displacement of the vibration system can be calculated through detection of change of the capacitor when the vibration system vibrates, so that the power of the loudspeaker can be reduced when the actual displacement of the vibration system exceeds the safety threshold. For electronic equipment adopting the loudspeaker structure, the displacement of each loudspeaker product can be detected in real time at the system end of the electronic equipment.

This invention relates to a heating method with uniform radiated microwaves and a device, in which, said method includes: a microwave device generates microwaves transmitted by a waveguide impedance converter and output to a corresponding couple cavity from the waveguide port to be reflected and scattered to output multiple microwave beams to the heating cavity uniformly from multiple couple holes on a sidewall of the couple cavity and these microwave beams enter into the heating cavity to radiate on the heated object, which greatly improves the un-uniform distribution of microwave energies in the heating cavity.

A SRAM has a plurality of four-transistor / no-load memory cells each operating in a precharge mode for maintaining stored data based on off-leak currents of MOSFETs. The SRAM has a reference voltage generator, an impedance converter, a plurality of word line drivers, and a plurality of word lines each extending along a row of the memory cells.

The invention discloses a radio frequency power amplifier, comprising a radio frequency amplification path, the radio frequency amplification path includes a multi-stage amplifying circuit, the multi-stage amplifying circuit includes at least one driving stage amplifier and at least one differential output stage amplifier, the output terminal of the driving stage amplifying circuit The differential output stage amplifier is connected through the interstage matching circuit, and the output terminal of the differential output stage amplifier is connected with the output matching circuit; wherein, the interstage matching circuit includes an interstage broadband balun or an interstage broadband balun impedance converter for The conversion of the radio frequency signal from unbalanced to balanced is realized, and the output matching circuit includes an output broadband balun impedance converter, which is used to convert the differential radio frequency signal into a single-ended radio frequency signal, and is coupled with the output gating circuit. The radio frequency power amplifier can realize 2G / 3G / 4G multi-band coverage with only one radio frequency amplification channel, which simplifies the architecture of the multi-mode multi-frequency radio frequency front-end chip and reduces the cost.

A circuit is provided where impedance converters (41-48) are provided such that active components (P1 to P8) can be switched off without power from the other active components leaking away through those components which are switched off.

A voltage detecting circuit including an impedance converter, an energy storage element, a current source and a comparing circuit is disclosed. The impedance converter is used for converting a high impedance voltage signal into a low impedance voltage signal. The energy storage element is electrically connected to the impedance converter, and receives the low impedance voltage signal. The current source is electrically connected to the energy storage element, and provides a discharging path of the energy storage element. The comparing circuit is electrically connected to the current source, and receives a voltage signal from the energy storage element. The voltage signal is compared with a predetermined reference voltage value stored in the comparing circuit so as to dynamically control operation of the power converter according to the comparing result.

The invention provides a Doherty power amplifier capable of realizing high efficiency in a wider frequency range. The Doherty power amplifier comprises a power distribution unit, a delay unit, a signal amplifying unit, a parasitic compensation unit and a power synthesizing unit; the signal amplifying unit comprises a main power amplifier and an auxiliary power amplifier; the power synthesizing unit comprises an impedance inverse device and an impedance converter; when the auxiliary power amplifier does not work, the load impedance of the main power amplifier is 110 to 130 ohms; and the impedance conversion rate of the impedance reverse device satisfied by the characteristic impedance of the impedance inverse device is 4. According to the power amplifier provided by the invention, the power amplifier has a high efficiency when the load impedance of the main power amplifier is 110 to 130 ohms and the main power amplifier withdraws 3-4 dB; as the characteristic impedance of the impedance reverse device is increased, the impedance reverse ratio of the impedance reverse device is controlled to be 4, thereby obtaining the high efficient Doherty power amplifier capable of satisfying the broadband requirement.

The invention relates to a radio-frequency push-pull power amplifier, belonging to the technical field of radio-frequency circuit. The radio-frequency push-pull power amplifier comprises the following four parts of a push-pull power transistor, an input matching network, an output matching network and a power supply bias circuit; the output matching network comprises an output balun impedance converter and an output matching circuit; the output balun impedance converter comprises a U-shaped coaxial cable and two identical straight coaxial cables that are overlapped in parallel and arranged on a printing circuit board horizontally, and two insulated leads; the two leads connect the internal conductor of the U-shaped coaxial cable with the internal conductor of the straight coaxial cable so as to form one conductor; the external conductors of two ends of the U-shaped coaxial cable are two low-resistance balance ports; the internal conductor of one end of the two straight coaxial cables is grounded and the other end thereof is a high-resistance unbalanced port; and the middle point of the external conductor of the U-shaped coaxial cable is connected with a direct current power and is grounded by a capacitance radio frequency. The radio-frequency push-pull power amplifier has symmetric structures, small space occupying, convenient processing and good repeatability, and greatly improves the electrical performance.

A condenser microphone includes a microphone chip and an LSI chip, which are stored in a microphone package having a sound hole. External sound enters the sound hole so as to propagate through the internal space of the microphone package, so that it is received by the microphone chip. The microphone package is designed to set the Helmholtz resonance frequency within the audio frequency range. The output signal of the microphone chip is supplied to an impedance converter included in the LSI chip. The output signal of the impedance converter is attenuated by an attenuation device with respect to the prescribed frequency band including the Helmholtz resonance frequency, which decreases when the condenser microphone is installed in the housing of an electronic device. Thus, it is possible to achieve the flat frequency characteristics in the output signal of the condenser microphone, which is thus improved in the S / N ratio.

An RF filter is disclosed. In an embodiment, the RF filter includes series-interconnected basic elements, each basic element having an electroacoustic resonator and impedance converters interconnected in series between the basic elements, wherein the impedance converters are impedance inverters and / or admittance inverters, and wherein the resonators of the basic elements are either only series resonators or only parallel resonators.

The invention relates to a double-frequency unequal power divider, which comprises a substrate, an input port 1, output ports 2 and 3, an inlet microstrip line, an upper and a lower double-frequency lambda / 4 composite left-right-handed transmission line branches, a resistor and two double-frequency impedance converters, wherein the input port 1 is connected with the inlet microstrip line, and the tail end of the inlet microstrip line is divided into the upper and the lower double-frequency lambda / 4 composite left-right-handed transmission lines; the junction of the upper and the lower branches is provided with the resistor; and the right sides of the tail ends of the upper and the lower branches are respectively added with a certain corner compensation and then are respectively connected with the dovetailed double-frequency impedance converters 1 and 2, thereby reaching the output ports 2 and 3. The double-frequency lambda / 4 composite left-right-handed transmission lines are adopted in the unequal Wilkinson power divider, so that the double-frequency unequal division function is realized, the volume of the device is decreased, the design process is simplified, and the design difficulty is reduced. In addition, the output ports adopt the dovetailed double-frequency impedance converters to realize the impedance match of the output ports. Signal reflection is decreased, and the mutual coupling among microstrip lines is reduced.

The method comprises: detecting the vibration of the water; transforming the impedance; isolating the DC; amplifying the signals; filtering the high frequency; making high and low threshold re-shaping process; using a single-board to make a decision according to the pulse count. The feature of the sensor is: setting the saddle weight on one side of the copper plate of the piezoelectric effect ceramic plate; the circuit features: composed of sensor, impedance converter circuit, DC isolation circuit, amplification circuit, high frequency filter circuit, re-shaping and threshold selecting circuit and single board; the sensor is connected to the impedance transforming circuit; the impedance transforming circuit is connected to the DC isolating circuit; the DC isolating circuit is connected to the amplifying circuit; the amplifying circuit is parallel-connected to the high frequency filter circuit; the output of the amplifying circuit is connected to the re-shaping and threshold selecting circuit; the re-shaping and threshold selecting circuit is connected to the single board.

A multiband Doherty amplifier having a configuration including a divider which divides an input signal into two, a carrier amplifier which amplifies one of the divided signals, a delay element which delays the other divided signal, a peak amplifier which amplifies the output signal of the delay element, an impedance converter which is connected to an output port of the carrier amplifier and performs predetermined impedance conversion and a combiner which combines the output signals of the peak amplifier and the impedance converter, wherein the electric length of the delay element is the same as the electric length of the impedance converter and the impedance converter has N (N≧2) cascade-connected impedance conversion transmission lines and performs substantially the same impedance conversion at each of the N frequencies.

The invention provides a radio frequency power amplifier. The radio frequency power amplifier comprises a radio frequency amplification path; the radio frequency amplification path comprises a multi-stage amplification circuit; and the multi-stage amplification circuit comprises an input radio frequency gating switch, a driving-stage amplifier, a stage matching network, an outputting-stage amplifier, an output matching network and an output gating network. The outputting-stage amplifier comprises first power amplifiers and second power amplifiers; the output matching network comprises first impedance converters and first transformers; one first power amplifier, one second power amplifiers and one first impedance converter compose a differential amplifier unit; and multiple differential amplifier units are provided, and the multiple differential amplifier units are connected in parallel. Through controlling the opening number of the differential amplifier units, switching of different power levels is realized, full coverage for high, intermediate and low frequency bands of 2G / 2G / 4G is accordingly achieved, and the cost of the radio frequency power amplifier is reduced.

A circuit device includes a multilayer circuit carrier, a first signal transmission line, a second signal transmission line, a signal line transition element, a first impedance transformer, and a second impedance transformer. The multilayer circuit carrier includes a first layer and a second layer. The first signal transmission line is on the surface of the first layer. The second signal transmission line is on the surface of the second layer. The signal line transition element passes through the first layer and the second layer, and has a first signal terminal and a second signal terminal. The first impedance transformer is on the surface of the first layer and electrically connected between the first signal transmission line and the first signal terminal. The second impedance transformer is on the surface of the second layer and electrically connected between the second signal transmission line and the second signal terminal.

The invention discloses an array antenna of a circularly polarized dielectric resonator, which can be used in the field of communication. The array antenna of the circularly polarized dielectric resonator comprises a feeder unit and four unit antenna arrays, wherein the four unit antenna arrays comprise four linearly polarized dielectric resonator units with single-end feed; the feeder unit comprises a power divider with a phase-shifting function, an impedance converter and a coupler and can assign equal power for each linearly polarized dielectric resonator unit, and the phase difference of adjacent linearly polarized dielectric resonator units is 90 degrees. The array antenna of the circularly polarized dielectric resonator has the advantages of circularly polarized property, high gain and front-back ratio, simple feed network, easy manufacture, and the like.

A high frequency composite switch module for a mobile communication device, wherein high frequency circuits such as a power amplifier, a circuit functioning as a transmitter / receiver switching circuit, a surface acoustic wave (SAW) filter for reception, and the like are modularized into one unit. A transmitter circuit includes a transmitter side impedance converter comprising an impedance matching circuit and an impedance converter circuit, a power amplifier and a power supply unit. A receiver circuit includes a receiver-side impedance converter comprising a phase shifting circuit and a SAW filter. The power amplifier and the impedance converter circuit are integrated into one IC chip. At least one of the matching circuit, the power supply unit and the phase shifting circuit is formed inside a multilayer board comprised of a conductor layer and a dielectric layer. The IC chip and the SAW filter are also mounted on the multilayer board.

The invention relates to a four-port multi-input-multi-output (MIMO) antenna with high isolation degree. The four-port MIMO antenna comprises a grounding metal plate (1), a dielectric substrate (2), four antenna radiation units (3), four 1 / 4 wavelength impedance converters (4), four 50-ohm microstrip lines (5) and four metal patches (6). The MIMO antenna is provided with four antenna units, the resonant frequency is 5.2GHz, and the nearest distance between adjacent two antenna units is only 4.75 millimeters and is about 0.082 times of wavelength of a free space corresponding to the resonant frequency; the MIMO antenna is compact in structure and small in size; and the coupling degree among the antenna units is below -19.5dB by a vertical polarization technology and a method of additionally arranging a coupling path on the premise of no increase on the antenna size, and the MIMO antenna is high in isolation degree and is expected to be widely applied to the technical field of wireless communication.