191results about How to "Lower input impedance" patented technology

A RFID transponder having a microchip or integrated circuit, an impedance-matching structure and a resonant structure mounted on at least one substrate and connected to each other by an electric field.

A reduction is achieved in the primary-side input impedance of a transformer (voltage transformer) as an output matching circuit without involving a reduction in Q-factor. An RF power amplifier includes transistors, and a transformer as the output matching circuit. The transformer has a primary coil and a secondary coil which are magnetically coupled to each other. To the input terminals of the transistors, respective input signals are supplied. The primary coil is coupled to each of the output terminals of the transistors. From the secondary coil, an output signal is generated. The primary coil includes a first coil and a second coil which are coupled in parallel between the respective output terminals of the transistors, and each magnetically coupled to the secondary coil. By the parallel coupling of the first and second coils of the primary coil, the input impedance of the primary coil is reduced.

A transimpedance amplifier, which is useful as an optical fiber preamplifier, is disclosed. The illustrative embodiment exhibits four characteristics. First, it minimizes the equivalent input noise current. Second, it has a wide bandwidth. Third, it has a reasonably large output voltage, and fourth, it is stable over wide temperature and voltage ranges. The illustrative embodiment comprises a transimpedance stage and a gain stage. Both stages employ a pure NMOS design which contributes to the above four advantages. Bandwidth is further increased over the prior art by the use of inductive loads. The inductive loads of the illustrative embodiment are not physical inductors, but transistor-based “active” inductors: the combination of a resistor connected in series with the gate of an NMOS transistor.

The invention discloses a transconductance-enhancing passive frequency mixer, which comprises a mixing stage and a biasing circuit, and further comprises a transconductance stage with a transconductance-enhancing function, a passive mixing switch pair and an enhanced load output stage, wherein the transconductance stage with a transconductance-enhancing function transforms an input radio-frequency voltage into a radio-frequency current; and frequency mixing of the radio-frequency current is achieved through the double-balance mixing switch pair, and the current after frequency mixing is transformed into a mid-frequency voltage for output through the transconductance-enhanced load output stage. As the transconductance stage uses a pre-amplifying transconductance-enhancing structure, transconductance is greatly enhanced, thus the same transconductance value can be achieved at a lower bias current, and an output mid-frequency current signal is generated after the radio-frequency current is modulated through the mixing stage. Voltage output is generated through a transresistance amplifier, and finally the mid-frequency voltage signal is obtained. As the transresistance amplifier uses a transconductance-enhancing structure, input impedance is reduced, and current utilization efficiency and port isolation are improved. The transconductance-enhancing passive frequency mixer provided by the invention has the characteristics of low power consumption, high conversion gain, good port isolation and the like.

The invention relates to a broadband wave absorption composite material with a multilayer structure and a preparation method thereof. The broadband wave absorption composite material is characterized in that the material comprises three parts, namely a surface layer, a sandwich layer and a bottom layer; the surface layer comprises, by mass percentage, 20 to 50 percent of carbonyl iron dust, 30 to 48 percent of polymer and 20 to 32 percent of fiberglass cloth; the sandwich layer comprises, by mass percentage, 2 to 6 percent of carbon nanometer tube, 56.4 to 58.8 percent of polymer and 37.6 to 39.2 percent of fiberglass cloth; and the bottom layer comprises, by mass percentage, 50 to 80 percent of carbonyl iron dust, 12 to 30 percent of polymer and 8 to 20 percent of fiberglass cloth. The broadband wave absorption composite material has the advantages of low surface density, thin thickness and high mechanical strength, and improves the bearing performance and the engineering application value.

The invention discloses a resonator and a filter. The resonator comprises a substrate, a bottom electrode layer, piezoelectric layers, top electrode layers and a connecting structure, wherein the bottom electrode layer is positioned on the upper side of the substrate; the bottom electrode layer is positioned on the lower sides of the piezoelectric layers integrally or partially; the top electrode layers are positioned on the upper sides of the piezoelectric layers,; and the connecting structure is positioned outside an effective area of the resonator and is in electric contact with the bottom electrode layer and / or the top electrode layers. According to the resonator, the connecting structure is arranged additionally to be connected with at least electrode layer, so that the input impedance of the resonator can be reduced effectively to improve the performance of the resonator and the filter (a Q value of the resonator is prevented from being reduced); and the connecting structure is positioned outside the effective area of the resonator, so that the normal operation of the resonator is not influenced.

An amplifier (100) comprises an input port (102) for receiving an input signal, an envelope port (104) for receiving an envelope signal indicative of an envelope of the input signal. The amplifier has a first transistor (M1) and a second transistor (M2). A first biasing circuit (120) is coupled to the envelope port (104) and is arranged to generate a first bias voltage dependent on the envelope signal. A summing stage (140) is coupled to the input port (102) for receiving the input signal, coupled to the first biasing circuit (120) for receiving the first bias voltage, coupled to a gate (g) of the first transistor (M1). A second biasing circuit (130) is coupled between the envelope port (104) and a gate (g 2) of the second transistor (M2), and is arranged to generate a second bias voltage dependent on the envelope signal.

A low-noise preamplifier with an electronic amplifying element having an input (2) and an output (4), and with a first transformer (6) having a primary winding (5) and a secondary winding (8) is characterized in that the input (2) of the electronic amplifying element is the base of a transistor, the gate (G) of a field effect transistor (FET) or the grid of a vacuum tube, and the output (4) of the electronic amplifying element is the collector, the drain (D) or the anode, the output current (Ip) being passed from the electronic amplifying element through the primary winding (5) of the first transformer (6) to the output (7) of the preamplifier, wherein the secondary winding (8) of the first transformer (6) is connected to the input (2) of the electronic amplifying element. This preamplifier can be operated with extremely low noise and at any input impedance, in particular, at 50 ohms or 75 ohms.

The present application relates to a near field communications (NFC) reader which includes an amplifier that drives an antenna. Capacitors of fixed value are connected in series between differential outputs of the amplifier and inputs of the antenna and form a series resonant circuit with the impedance of the antenna. Variable capacitances are provided in series with the fixed value capacitors, and the capacitance of these variable capacitances can be adjusted to compensate for manufacturing tolerances in the fixed value capacitors which cause a frequency offset between a desired resonant frequency of the series resonant circuit its actual resonant frequency, and to compensate for changes in the input impedance of the antenna that occur as the distance between the antenna of the reader and an antenna of an NFC tag changes.

The invention discloses a dual-frequency receiving antenna and a dual-frequency rectifying antenna. The dual-frequency receiving antenna and the dual-frequency rectifying antenna are used for solving the problems that an existing dual-frequency receiving antenna is large in size and small in gain, an existing dual-frequency rectifying antenna is large in size, can not receive weak energy and is not suitable for remote transmission, and a rectifying circuit is poor in reliability. The dual-frequency receiving antenna comprises a rectangular radiating patch. A Z-type groove used for achieving dual-frequency characteristics is formed in the radiation patch. The lower end of the radiation patch is sequentially connected with a dielectric substrate layer and a metal earth plate through a coaxial line. The coaxial line is in circuit connection with the rear end of the radiation patch. An air dielectric layer is formed between the radiation patch and the dielectric substrate layer. The portions, arranged between the radiation patch and the dielectric substrate layer, outside the coaxial line are provided with metal sheets in a bilaterally-symmetric mode. The upper ends of the metal sheets are connected with the radiation patch. The lower ends of the metal sheets are connected with the dielectric substrate layer. One end face of the radiation patch is further connected with the metal sheets connected with the dielectric substrate layer. The dual-frequency receiving antenna and the dual-frequency rectifying antenna can be widely applied in the fields of communication, medical treatment, industry and the like, for microwave power transmission.

The invention discloses a method for manufacturing an Archimedes helical antenna. By means of integrated design of an index helical antenna and a sine wave meander Archimedes helical antenna and impedance conversion characteristics of the index helical antenna, high input resistance of the Archimedes helical antenna is decreased to 50 omega, the electrical length of an antenna arm can be increased by means of the meander Archimedes helical antenna, and miniaturization is achieved. When the impedance conversion ratio of two ends of a Balun of a microstrip line with indexes gradually changing is close to one, conversion between an unbalanced mode and a balanced mode can be achieved in a super broadband with a short length. A back cavity with a profile depth the same as the length of the Balun is adopted to acquire single-way radiation. By means of the method, the antenna can work within the frequency band range from 0.8GHz to 9.4GHz, the profile depth is 10mm, the aperture is 100mmm, and the aperture area is decreased by 78.62 percent compared with the traditional Archimedes helical antenna working in the same frequency band.

The invention relates to a combined near field communication and wireless power transmitter device comprising a first antenna coupled to antenna tuning network and capable of coupling to one or more second antennae in the near field of the first antenna with coupling characteristics, means for communicating wirelessly using said first antenna with a near field communication device in a near field communication mode, and means for transmitting wirelessly power using said first antenna to another device in the vicinity of the first antenna in a power transmission mode. In power transmission mode, the antenna tuning network operates in resonance and has an initial input impedance which is configured to change if there is a change in the coupling characteristics during power transmission, for example charging. The invention also relates to a method of transmitting power to a mobile device for example for charging purposes.

The invention discloses a current feedback operational amplifier circuit comprising a power supply, a bias current supply unit, a first common base-common emitter current mirror, a second common base-common emitter current mirror, a static bias circuit, an input buffer stage, a voltage conversion stage and a drive output unit, wherein the drive output unit comprises a bias voltage circuit and an output buffer stage; the bias current supply unit is respectively connected with the input buffer stage through the first common base-common emitter current mirror and the second common base-common emitter current mirror and used for supplying bias current; and the static bias circuit is respectively connected with the inverted input end of the input buffer stage and the voltage conversion stage and used for stabilizing a static working point of the inverted input end. The current feedback operational amplifier circuit has the advantages of lower offset voltage, stronger on-load capacity and higher conversion rate and is beneficial to improvement of the precision and the linearity of the entire operational amplifier.

An RF transceiver integrated circuit has a novel segmented, low parasitic capacitance, internal loopback conductor usable for conducting IP2 self testing and / or calibration. In a first novel aspect, the transmit mixer of the transceiver is a current mode output mixer. The receive mixer is a passive mixer that has a low input impedance. In the loopback mode, the transmit mixer drives a two tone current signal to the passive mixer via the loopback conductor. In a second novel aspect, only one quadrature branch of the transmit mixer is used to generate both tones required for carrying out an IP2 test. In a third novel aspect, a first calibration test is performed using one quadrature branch of the transmit mixer at the same time that a second calibration test is performed using the other quadrature branch, thereby reducing loopback test time and power consumption.

Providing a driver for semiconductor switch element capable of securing a sufficient drive power and reliably turning off the semiconductor switch element. The driver includes a converter section 2 which includes a switching element Q1 and which is configured to output a desired DC voltage by switching the switching element Q1, a control section 1 configured to control the switching operation of the switching element Q1, capacitors C1A, C1B charged by the output of the converter section 2, turn-on circuits 31A, 31B configured to supply gates of a bidirectional switch element 4 using electric charges stored in the capacitors C1A, C1B with drive powers to turn-on the bidirectional switch element 4, and turn-off circuits 32A, 32B configured to discharge the capacitors C1A, C1B to turn-off the bidirectional switch element 4 in response to the halt of the switching operation of the switching element Q1 by the control section 1.

An apparatus and method for an interface for transmitting high speed data between circuits. A driver circuit produces first and second differential currents from a digital signal that drive first and second transmission lines. A receiver is connected through first and second terminating resistors to said transmission lines. The resistive elements are in turn connected to first and second common base amplifiers where the differential currents are converted to a differential voltage. The input impedance to the first and second common-base amplifiers is further lowered by a differential amplifier having inputs connected to the inputs of the common-base amplifiers, and an output connected to the bases of said common-base amplifiers. As a result, voltage conversion of the differential signals takes place in the common-base amplifiers and not in the terminating resistors, reducing the level of the differential currents and permitting an increase in the digital data rate. In addition, a common-gate amplifier configuration of the present invention is provided as well as a method for dynamically determining an optimal transmit power level for the driver circuit and for performing an accelerated bit error rate measurement.

Provided are a wireless power transmission receiver and a system including the same, particularly to a receiver and transmitter transmitting power from one transmitter to a plurality of receivers at the same time by wireless. According to the present invention, the wireless power receiver comprises a receiving coil unit receiving power from a transmitter by a resonance coupling method; and a power receiving unit receiving power from the receiving coil unit to provide the power to a load resistor, wherein an input impedance of the power receiving unit is adjusted according to power consumed by a plurality of receivers. Therefore, power transmission efficiency of the wireless power receiver and transmitter can be improved.

A RFID transponder having a microchip or integrated circuit, an impedance-matching structure and a resonant structure mounted on at least one substrate and connected to each other by an electric field.

A spiral antenna having a pair of antenna arms mounted on a dielectric substrate. A balun is included to connect the antenna which has an impedance of 100 ohms to a 50 ohm cable. Unique features of the spiral antenna design provide for size reduction at a given lowest required frequency of operation. The spiral antenna has dielectric material layers positioned on both side of the antenna's metal arms. In addition, the antenna input impedance is reduced from the normal 100 ohm input impedance to approximately 50 ohms due the dielectric material.

A low-noise preamplifier with an electronic amplifying element having an input (2) and an output (4), and with a first transformer (6) having a primary winding (5) and a secondary winding (8) is characterized in that the input (2) of the electronic amplifying element is the base of a transistor, the gate (G) of a field effect transistor (FET) or the grid of a vacuum tube, and the output (4) of the electronic amplifying element is the collector, the drain (D) or the anode, the output current (Ip) being passed from the electronic amplifying element through the primary winding (5) of the first transformer (6) to the output (7) of the preamplifier, wherein the secondary winding (8) of the first transformer (6) is connected to the input (2) of the electronic amplifying element. This preamplifier can be operated with extremely low noise and at any input impedance, in particular, at 50 ohms or 75 ohms.

An adjustable bandgap reference voltage comprises means for generating current proportional to absolute temperature comprising first means connected to terminals of a core and designed to equalize voltages across the terminals, means for generating a current inversely proportional to absolute temperature connected to the core, and an output module designed to generate the reference voltage; the first processing means comprise a first amplifier possessing a stage, biased by the current inversely proportional to absolute temperature, arranged according to a folded setup and comprising first PMOS transistors arranged according to a common-gate setup, and a stage whose input is connected to the amplifier output and whose output is connected to the first stage input and to a terminal of the core, the second generating means comprise a follower amplifier setup connected to a terminal of the core and separated from the first amplifier, the output module is connected to the feedback stage.

A transimpedance amplifier, which is useful as an optical fiber preamplifier, is disclosed. The illustrative embodiment exhibits four characteristics. First, it minimizes the equivalent input noise current. Second, it has a wide bandwidth. Third, it has a reasonably large output voltage, and fourth, it is stable over wide temperature and voltage ranges. The illustrative embodiment comprises a transimpedance stage and a gain stage. Both stages employ a pure NMOS design which contributes to the above four advantages. Bandwidth is further increased over the prior art by the use of inductive loads. The inductive loads of the illustrative embodiment are not physical inductors, but transistor-based “active” inductors: the combination of a resistor connected in series with the gate of an NMOS transistor.

The invention discloses wireless communication equipment. A first antenna and a second antenna are arranged on the wireless communication equipment. The electrical length of the first antenna is N times of that of the second antenna, and N is an integer larger than or equal to one. The first antenna and the second antenna are arranged on a printing circuit board in a common ground connection mode, namely, the first antenna and the second antenna share the same grounding point, so that the input impedance of the grounding point of the first antenna and the grounding point of the second antenna is reduced, and energy fed through the antennas is made to be distributed in a relatively even mode in the horizontal direction and the perpendicular direction of the printing circuit board. Consequently, SAR is reduced on the condition that the communication quality of the wireless communication equipment is not reduced.

The invention discloses a broadband balance power amplifier based on GaN. The broadband balance power amplifier based on the GaN comprises a Lange coupler, a microstrip transmission line, a Banding metal wire, a filter inductor, a stabilizing resistor and a wide band gap GaN-based HEMT. A biasing circuit of the power amplifier comprises a T-shaped connector, the microstrip transmission line, the filter inductor, the stabilizing resistor and the GaN-based HEMT, the GaN-based HEMT (H) is an HEMT pipe core with the type of NRF01-02a, and a four-line 3dB coupling Lange coupler with the characteristic impedance of 50 ohms is selected and used as the Lange coupler. The broadband balance power amplifier based on the GaN is simple in structure and low in cost, the Lange coupler is adopted for constructing the structure of the balance power amplifier, a multi-section impedance matching technology is adopted for designing an input / output matching network, the power amplifier broadband characteristics are achieved, and within the 115-315 GHz frequency band, the power amplifier linear gain is larger than 12 dB, and the saturation output power is larger than 8 W.

This invention is about a readout apparatus and method for time-of-flight and energy measurements with silicon photomultipliers (SIPM) coupled to a scintillator. The timing measurement can be as accurate as 50 ps or below, after calibration. The energy is measured using a time-over-threshold technique, and the energy resolution is only constrained by the scintillation statistics. In order to achieve low power of 10 mW per channel, a low impedance input amplifier and analogue time-to-digital converters (TDCs) based on time interpolation are used. The readout circuit can be triggered by a single photoelectron (p.c.) with a signal-to-noise ratio (SNR) above 20 dB. The said readout circuit operates with SiPMs of different gain, polarity and matrix size. The preferred embodiment of the readout apparatus is a multi-channel application specific integrated circuit (ASIC) with 64 channels.

The present invention is related to a coplanar coupled-fed multiband antenna for the mobile communication device. The antenna mainly comprises a dielectric substrate, a ground plane located on one surface of the dielectric substrate, and a radiating portion, a shorting metal portion, and a feeding portion, which are all on the same surface of the dielectric substrate near one edge of the ground plane. One end of the shorting metal portion is connected to the radiating portion, and the other end is connected to the ground plane. The feeding portion comprises a first feeding metal portion and a second feeding metal portion. The first feeding metal portion has a feeding point for the antenna. One end of the second feeding metal portion is connected to the radiating portion, and there is a gap between the second feeding metal portion and the first feeding metal portion.

A power device is formed by a thyristor and by a MOSFET transistors, series-connected between a first and a second current-conduction terminal. The power device moreover has a control terminal connected to an insulated-gate electrode of the MOSFET transistor and receiving a control voltage for turning on / off the device, and a third current-conduction terminal connected to the thyristor for fast extraction of charges during turning-off. Thereby, upon turning off, there are no current tails, and turning off is very fast. The power device does not have parasitic components and consequently has a very high reverse-bias safe-operating area.

The invention relates to a reading circuit based on relaxor ferroelectric monocrystal pyroelectricity, which can realize the outputting of a relaxor ferroelectric monocrystal pyroelectric signal. The output current signal of the relaxor ferroelectric detector is converted into a voltage signal through an CTIA input-stage circuit module, the voltage signal is output after amplification, a double sampling hold circuit samples the signal twice, and a multichannel transmission circuit outputs the signals in each channel after conduction. The circuit modules are integrated on an integrated circuit chip and connected with a detector chip, and the control signal of the circuit modules is provided by an external drive circuit, thus the integrated circuit chip can effectively read the signal of the relaxor ferroelectric detector.

Crossover networks modified to render audible colorations or frequency / phase emphases observed in some crossover networks of the prior art. Circuit topologies of prior art crossover networks are modified such that an additional pole appears in the transfer functions of one or more low-frequency pass crossover filters. In addition, the characteristic input impedance of one branch of the modified crossover network is reduced, typically to a value of approximately one-half the design characteristic impedance of the unmodified crossover networks.

The invention discloses a miniature measurement and control system fit for a high-field asymmetric waveform transference tube. The system comprises a man-machine interaction module, an upper computer system and a measurement and control circuit module, wherein the measurement and control circuit module comprises a plurality of sub-circuit modules; an operator sends an operation command and observes a detection result through a friendly instrument operation interface provided by the upper computer system and the man-machine interaction module; the upper computer system is connected with the sub-circuit modules in the measurement and control circuit module; and the sub-circuit modules are connected with corresponding components in the high-field asymmetric waveform transference tube to generate measuring signals necessary for detecting substance ingredients of the high-field asymmetric waveform transference tube and detect a signal output by the high-field asymmetric waveform transference tube at high precision. The miniature measurement and control system provided by the invention is fit for high-field asymmetric waveform transference tubes with different sizes and manufactured by various techniques, and the system has the advantages of low noise, high integration degree, good reliability and anti-interference capability, and quick and simple operation, and the like.