473 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.

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.

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 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.

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.

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.

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.