46results about How to "High common mode rejection" patented technology

A chopper-stabilized amplifier has switching networks arranged to support a high frequency clocking signal and to provide a high common mode rejection and a high rejection of an offset component of an input signal. A magnetic field sensor includes a Hall effect element coupled to a modulation circuit. The modulation circuit provides a signal to the chopper-stabilized amplifier. The chopper-stabilized amplifier provides an output signal to a low pass filter, which provides an output signal from the magnetic field sensor.

Detecting binding events between first and second molecules (e.g., ligands and proteins) includes mixing at the first end of a test channel, then separating the bound/unbound molecules (e.g., using electrophoresis) by causing the molecules to move down the channel such that groups of bound/unbound molecules move along the channel at different rates. The groups are then detected, measured and compared against established reference data to determine whether a binding event has occurred. A reference channel is utilized to provide reference data and to identify unbound molecule groups. Radiant energy and a bolometer are utilized to measure the molecule groups

A low power, low noise amplifier system includes at least one amplifier having first and second differential input terminals, first and second differential output terminals and providing a differential output; first and second input capacitors interconnected with the first and second differential amplifier input terminals; first and second feedback circuits containing first and second feedback capacitors, respectively, interconnected with the amplifier differential input and output terminals; an input chopper switch circuit for receiving a low frequency differential input and selectively, alternately swapping those low frequency differential inputs through the input capacitors to the differential input terminals of the amplifier; an output chopper switch for receiving and selectively, alternately swapping the amplifier differential outputs synchronously with the input chopper switch circuit; and a low pass filter responsive to the swapped differential outputs for providing a low noise, low power amplification of the low frequency differential inputs.

The invention discloses a single-converted-to-double low noise amplifier with a highly balanced and stabilized differential output gain phase. The amplifier comprises a common source or common emitter input amplifying transistor pair which comprises a first transistor and a fourth transistor, a common gate or common base amplifying transistor pair which comprises a second transistor and a third transistor, a tail current source pipe and output load circuits with tight coupling differential inductors; a fourth inductor L4 and a fifth inductor L5 are tight coupling differential inductors; C1 and C2 are differential capacitors with the same capacitance values; L0 and L1 also are tight coupling differential inductors. For the amplifier disclosed by the invention, since output loads adopt the tight coupling differential inductors L4 and L5 and the differential capacitors C1 and C2 for resonance, the balance and the stability of the differential output gain phase are improved, and the high-impedance tail current source pipe M5 can well restrain a common mode signal. The amplifier disclosed by the invention has excellent robustness when the PVT (Pressure Volume Temperature) and a working frequency point are changed, and at the same time, the amplifier has an excellent anti-interference capacity for the medium base noise.

The invention discloses a balanced dual-pass band filter which comprises a three-layer circuit structure consisting of a single face microwave dielectric substrate and a double face microwave dielectric substrate. A slot line is arranged in a middle line of a metal face between the single face microwave dielectric substrate and the double face microwave dielectric substrate. The single face microwave dielectric substrate is symmetrically provided with a first microstrip transmission line and a second microstrip transmission line. The double face microwave dielectric substrate is provided with a third microstrip transmission line and a fourth microstrip transmission line symmetrically distributed with the first and second microstrip transmission lines in relation to the slot line. The single or double face microwave dielectric substrate is further provided with a first resonator, and a second resonator, a third resonator as well as a fourth resonator and a fifth resonator symmetrically distributed inside and outside the third and fourth microstrip transmission lines in relation to the first resonator, respectively. Common mode rejection is formed through transition from the balanced microstrip line to the slot line, the frequency of a first pass band is adjusted by controlling the length of two pairs of the microstrip lines and the slot lines, and the frequency of a second pass band is controlled by controlling the size of the second and third resonators.

The invention discloses an amplifier eliminating direct current offsets. The amplifier eliminating the direct current offsets comprises a pre-amplifier circuit, a direct current extracting circuit and an isolating circuit, wherein the direct current extracting circuit is used for extracting direct current component signals output by the pre-amplifier circuit, and the isolating circuit is used for generating an electrical current which is identical in size and opposite in direction with direct current offset currents generated by direct current offset voltages carried by two signals to be measured in the pre-amplifier circuit and feeding back and inputting the electrical current to the pre-amplifier circuit according to the received direct current component signals of the direct current extracting circuit. The amplifier sends signals output by a three-operational-amplifier output end to the direct current extracting circuit, extracts the direct current component signals output by the pre-amplifier circuit, and converts direct current components to analogue signals and outputs the analogue signals to the isolating circuit, the isolating circuit converts input voltages to constant flow sources and feeds back to an input end of the pre-amplifier circuit in an inverse mode, and therefore dynamic elimination of the direct current offsets is achieved.

The invention provides a micro-strip balanced filter which comprises two micro-strip band-pass filters. Structures of the two micro-strip band-pass filters are identical, the two micro-strip band-pass filters are symmetrically connected with each other, and source-load coupling structures generate transmission zero points inside edges of pass bands and stop bands under excitation actions of different-mode signals, so that the internal frequency selectivity of the pass bands is improved, and the stop bands are deepened; two common-mode signal transmission zero points are generated in each different-mode pass band by a corresponding central loaded stepped-impedance open-circuit branch and a folded oscillator loaded on a corresponding feeder, so that the common-mode rejection capacity is improved. The micro-strip balanced filter has the advantages of high frequency selectivity, low insertion loss, wide stop bands and compact structure.

The invention discloses a TM dual-mode balanced band-pass filter based on SIW (substrate integrated waveguide). The band-pass filter comprises a first dielectric substrate, a first metal plate, a second dielectric substrate, a second metal plate and a third dielectric substrate which are sequentially and coaxially arranged from top to bottom, micro-strip lines are arranged on the first dielectricsubstrate and the third dielectric substrate, a first rectangular gap rotating anticlockwise by 38 degrees is formed in the first metal plate, the second dielectric substrate is provided with a metalthrough-hole array and two perturbation metal holes, and a second rectangular gap rotating clockwise by 38 degrees is formed in the second metal plate. According to the band-pass filter, two poles aregenerated in a pass band, a transmission zero is generated on each side of the pass band, and the band-pass filter has high selectivity. Besides, the position and the size of a coupling gap are designed, six modes near TM120 and TM210 modes are effectively inhibited, and good wide stop-band inhibition performance is achieved. Magnetic walls are formed in the middles of the micro-strip lines underexcitation of a common mode, and magnetic current cannot enter a resonant cavity through the coupling gap, so that high common mode rejection is achieved within a wide frequency band range.

The invention provides a double-frequency differential band-pass filter based on a branch load resonator. The problems of high insertion loss, low selectivity and inflexible design of a filter are solved. Two opposite quasi-interdigital coupling branch knot load resonators, a stepped impedance microstrip line in three-line interdigital coupling with the quasi-interdigital coupling branch knot loadresonators and U-shaped microstrip lines on the two sides are printed in the middle of the upper surface of a dielectric substrate. The lower surface of the substrate is etched with two linear L-shaped stepped impedance slot lines which rotate 90 degrees counterclockwise. The above structures are all symmetrical about the center of the dielectric substrate. All the structures are symmetrical about the center of the central point of the substrate and are bent by 90 degrees relative to the stepped impedance slot lines, so that the size of the filter is greatly reduced; through quasi-interdigital coupling and three-line interdigital coupling structures, the insertion loss of the filter is reduced and three transmission zeros are formed, so that the selectivity of the filter is enhanced; anda branch knot loaded in the center is in an open circuit mode and a short circuit mode, is independent and adjustable in frequency, meets different requirements, and is used for a radio frequency front end of a wireless communication system.

The invention relates to the technical field of IGBT driving and provides a driving method and device for an IGBT provided with a push-and-pull isolating power source. The driving device adopted in the method comprises a primary side driving circuit, a secondary side driving circuit and a push-and-pull DCDC isolating power source circuit; a PWM shaping circuit of the primary side driving circuit is connected with the input end of the secondary side driving circuit through a photoelectric isolating circuit; the feedback end of the secondary side driving circuit is connected with a fault signal latch circuit of the primary side driving circuit through a fault feedback circuit; the output end of the secondary side driving circuit is connected with an IGBT module; the input end of the PWM shaping circuit, the output end of the fault signal latch circuit and the push-and-pull isolating power source circuit are connected with a driver interface. By controlling primary and secondary distributed capacitance of a transformer, the common-mode rejection capacity of the driving device is improved, and the anti-jamming capability of the driving device is enhanced; the isolating power source circuit is simplified, and the cost of the driving device is lowered; the size of the driving device is reduced, and the driving device is high in practicability and reliability.

An amplifier comprising a differential amplifier configured to be provide a comparator function, and a gain trimming circuit is electrically configured to provide gain trimming using a T-network comprising a varistor element. In addition, a method of trimming the gain of a differential amplifier, comprising the steps of a first step, (a) providing the differential amplifier comprising resistors in both of its paths, a second step, (b) providing a varistor in a T-network between both said paths; and lastly, a third step, (c) trimming the gain of the differential amplifier by adjusting the varistor's resistance.

The invention discloses a signal compensation circuit of a medical remote monitoring system. The signal compensation circuit comprises an anti-interference circuit, a compensating circuit and a differential output circuit, wherein the anti-interference circuit receives signals in a signal transmission channel of the medical remote monitoring system, removes interference signals through filtering by a composite circuit consisting of a diode D4, a triode Q1, a voltage stabilizing tube Z1 and a thyristor VTL1, and finally processes and outputs single-frequency stable signals by a frequency-selecting filter circuit consisting of a resistor R5, a resistor R6, a capacitor C7, inductors L2 and L3 and a capacitor C8, and the signals then enter the differential output circuit and are output; the compensating circuit is used for providing stable power supply for the anti-interference circuit, compensating nonlinearity of interference suppressing signals of the anti-interference circuit and providing compensating signals for the output signals of the differential output circuit, so that amount of attenuation in the signal transmission process is further compensated, the signals in the signaltransmission channel of the medical remote monitoring system are effectively stabilized, and the phenomenon of signal attenuation is eliminated with the compensation method.

The invention belongs to the field of wireless communication, and particularly relates to a small broadband differential excitation dual-mode and dual-polarized base station antenna in this field. Theantenna comprises a first dielectric plate, a second dielectric plate a third dielectric plate, a reflection plate, a coaxial connector, a radiation patch, a driving branch and baluns. The first dielectric plate is horizontally arranged at the uppermost layer of the whole antenna; the reflection plate is horizontally arranged at the lowest layer of the whole antenna; the pair of mutually orthogonal baluns are arranged between the first dielectric plate and the second dielectric plate, and the first dielectric plate and the reflection plates are respectively perpendicular to the baluns up anddown; the orthogonal surfaces of the orthogonal baluns are respectively printed with the second dielectric plate and the third dielectric plate to allow the second dielectric plate and the third dielectric plate to be mutually perpendicular to the first dielectric plate and the reflection plate. The small broadband differential excitation dual-mode and dual-polarized base station antenna ensuresthe miniaturization while ensuring the broadband.

The invention discloses a low-voltage high-common-mode-rejection amplifier. The low-voltage high-common-mode-rejection amplifier comprises a basic circuit constructed by connection of differential pair transistors and a common-mode rejection amplifying circuit, and is provided with a common-mode feedback circuit consisting of field-effect transistors P2B, P2C, N2B and N2C, and a current summing circuit consisting of field-effect transistors N3, N4, P6, P5, P3A and P3B; the field-effect transistors P2B and P2C of the common-mode feedback circuit and the field-effect transistor P2A of the common-mode rejection amplifying circuit are in common-gate connection with a common-gate reference voltage VCP; power supply end current sources P1A and P1B and ground end current sources N1A and N1B of the common-mode rejection amplifying circuit mirror current flowing through onto the field-effect transistor Nb through the current summing circuit; the field-effect transistor Nb and a resistor Rb are in common-mode matching with the field-effect transistor Na and a resistor Ra through which reference current IREF flows; and current flowing through the field-effect transistor N2A in the common-mode rejection amplifying circuit is clamped to be close to the reference current IREF. Through feedback automatic biasing in the amplifier, the common-mode rejection effect of the circuit is enhanced. Meanwhile, the amplifier can work under low supply voltage.

The invention discloses an electric energy meter detection circuit and an intelligent electric meter. The electric energy meter detection circuit comprises a high-voltage detection unit, a low-voltagedetection unit, and a main control unit. The input end of the main control unit is respectively connected with the output ends of the high-voltage detection unit and the low-voltage detection unit, the high-voltage detection unit is used for judging power failure and power-on of an electric meter, and the low-voltage detection unit is used for controlling the power-on work of the electric meter;a high-voltage rectifying circuit and a high-voltage voltage division circuit are arranged in the detection circuit, few capacitors are arranged in the high-voltage rectifying circuit and the high-voltage voltage division circuit, detection signals are transmitted more quickly by adopting high-voltage level signals, the response time of power failure of the electric meter is shortened, and the reliability of detection data of the electric energy meter is improved. Extra battery power consumption caused by insufficient power-down retention time can be avoided, power-down switching-off can be configured without configuring a high-capacity electrolytic capacitor, and the cost of a detection circuit is saved.

The invention discloses a mounting structure of a power EMI filter. The mounting structure comprises a filter body, an isolation hood and load in the isolation hood. The filter is provided with a metal shielding outer shell, the isolation hood is connected with a ground wire, an output wire and an input wire of the filter body are arranged at the two ends of the filter respectively, the input wire is electrically connected with a power component, and the output wire is electrically connected with the load. The mounting structure is characterized in that the filter body is further arranged in the isolation hood which is provided with a wire outlet where the output wire penetrates through, and the metal shielding outer shell is electrically connected with the isolation hood through a connecting piece. Welding or a screw fixed mounting mode in the prior art is replaced, dismounting and replacing of the filter are facilitated, and good electric connection of the filter body and the isolation hood is guaranteed; the ground wire is connected to the bottom of a horizontal supporting plate, and the influence of ground resistance on the filter is reduced to the largest extent. The input wire and the output wire of the filter body are fully isolated, and electromagnetic coupling between the input wire and the output wire is reduced.

The invention discloses an electric power working condition Internet-of-things monitoring device based on artificial intelligence and a using method, relates to the technical field of electric power working condition monitoring, and aims to solve the problem that working data of a monitoring device cannot be timely and effectively shared with a remote terminal due to lack of corresponding Internet-of-things intersection between the monitoring device and the remote terminal, the monitoring effect of the electric power working condition is poor, and the intelligent monitoring requirement of theelectric power working condition cannot be met. An insulation pad is arranged in the device shell, a processor is arranged in the device shell, a current transformer and a voltage transformer are arranged on one side of the processor, and a relay protector and a temperature sensor are arranged on the other side of the processor. The output ends of the current transformer, the voltage transformer and the temperature sensor are all electrically connected with the input end of the processor, a clamping groove is formed in one end of the device shell, a threaded hole is formed in the clamping groove, and a fixing block is arranged below the device shell.