55results about "One-way transmission networks" patented technology

A technique for attenuating common mode transient events uses a differential receiver circuit including a band-stop filter having a stopband f_SB around a notch frequency f_n of a received signal. The differential receiver circuit includes a first high-pass filter coupled in series with the band-stop filter. The notch frequency f_n is less than a carrier frequency f_c of a signal received by the differential receiver circuit. The band-stop filter may include a buffer circuit and a notch filter coupled in series with the buffer circuit. The notch filter may have a second stopband around the notch frequency f_n. The differential receiver circuit may have a propagation delay that is independent of a pulse width of common mode transient energy attenuated by the differential receiver circuit.

A multi-port active circulator where each of plurality of FET transistors has (i) a gate connected to an associated port of the multi-port active circulator via a capacitor of an associated one of a plurality of first RF chokes, each of the first RF chokes being connected to a gate of an associated FET transistor of said plurality of transistors, the associated port of said associated FET transistor and to a power supply bias connection; (ii) a source connected to a common point; and (iii) a drain connected to the gate of the same FET transistor by a feedback circuit and connected to the gate of a neighboring FET transistor via a capacitor of one of a plurality of second RF chokes, each of which coupling gates and drains of neighboring FET transistors via capacitors thereof and being connected to another power supply bias connection.

The present invention provides a sampling adaptive direct-current electronic transformer detection converter. A main control module controls the channel switching of the first input channel, second input channel and third input channel of a multiplexer, and therefore, large current input signals are inputted through a first input channel port and are converted into small voltage signals through amilliohm-level precision resistor, small current input signals are inputted through a second input channel port and are converted into small voltage signals through a conventional compact resistor, and the small voltage signals are inputted through a third input channel port. Thus, the large current input signals, the small current input signals and the small voltage signals can be adaptively converted by the converter of the present invention. The sampling of different types of analog quantity input signals can be completed, and the analog quantity input signals can be converted into corresponding coded digital signals; the coded digital signals are sent to a backend calibrator body device; and therefore, the closed-loop calibration of a direct-current transformer can be realized, and a technical problem that existing direct-current transformer closed-loop test needs to replace a converter repeatedly can be solved.

The invention provides an ALC circuit and a radio frequency signal source. The ALC circuit comprises an input port, a radio frequency link connected to the input port, a feedback loop connected to theradio frequency link and an output port, wherein the radio frequency link comprises a variable attenuator connected to the input port, a first radio frequency amplifier connected to the variable attenuator, a temperature compensation module connected to the first radio frequency amplifier, a second radio frequency amplifier connected to the temperature compensation module and a power divider connected to the second radio frequency amplifier; the feedback loop comprises a detector connected to the power divider, a digital acquisition module connected to the detector, a digital processing module connected to the digital acquisition module and a digital-to-analogue conversion module connected to the digital processing module. According to the ALC circuit and the radio frequency signal source, the influence of the temperature on the gain of the radio frequency link is reduced, so that the calibration time can be saved, and the production efficiency can be improved.

The present invention is an electronic isolator that provides low input to output insertion loss, high output to input insertion loss, and substantial asymmetric isolation between a source circuit and a load circuit. The invention actively reduces noise and reflected power appearing on the isolator output. In numerous embodiments, the invention operates in circuit applications from dc through millimeter wave. Multistage electronic isolator embodiments provide increased isolation and greater noise reduction. In other embodiments, the electronic isolator also removes noise appearing on its input. In another embodiment, the invention is configured for high power applications. This embodiment includes circuitry for redirecting power away from the load into resistors or other dissipative elements. In another embodiment, the electronic isolator is configured to remove signal distortion produced by one or more power amplifiers in the system.

The invention discloses a multilevel filter circuit. Good sensitivity is obtained through matching of multi-level operational amplifiers; and when an audio signal enters, various interference noises mixed in the audio signal are filtered. The filtering validity and anti-interference performance are ensured by setting good narrow-band band-pass; cut-off frequency of a high end and a low end is adjusted through a potentiometer; alternating current hums can be inhibited; bad signals and interference noises are eliminated; and the anti-interference capability of a circuit is improved.

The invention discloses a filter and a quality factor compensation method thereof. The filter comprises a first filter circuit, a second filter circuit, a third filter circuit, an input circuit and an output circuit. The first filter circuit and the second filter circuit are connected in series. The third filter circuit is in parallel connection with the first filter circuit and the second circuit. The input circuit is connected with the first filter circuit and the third filter circuit. The output circuit is connected with the second filter circuit and the third filter circuit. The advantages and beneficial effects are that through compensation of a quality factor Q value of the filter, the relatively ideal filtering characteristics can be maintained when the operational amplifier performance of the filter is not good. Therefore, the Q value of the filter is compensated, the gain bandwidth product of an operational amplifier needs not to be increased, the area of a resistor is avoided, the power consumption is reduced, and the filter is simple in structure and high in controllability.

The invention provides a filtering device and a filtering method. The filtering device includes a low-pass filter (LPF), a noise estimation circuit and a combining circuit. The LPF receives and filters a pre-filtering signal to generate an output signal of the filtering device. The noise estimation circuit estimates an estimated noise signal according to the output signal and the pre-filtering signal. The combining circuit subtracts the estimated noise signal from an input signal of the filtering device to generate the pre-filtering signal. Therefore, the area consumed by the filtering device can be effectively limited, and undesired noise can be effectively filtered out.

The invention discloses a small signal amplification device, which solves the problem that an existing small signal amplification device is loud in noise, complex in circuit and high in cost. The device comprises a power processing unit and a signal amplification filter unit, wherein the signal amplification filter unit comprises first and second emitter followers, a first-stage amplifier, a second-stage amplifier, a third-stage amplifier, a band-pass filter and first and second wave traps; the first emitter follower receives a small signal and outputs the small signal to the first-stage amplifier, the band-pass filter filters the signal output by the first-stage amplifier, the second-stage amplifier receives a filtered output signal, the first wave trap filters interference of the signaloutput by the second-stage amplifier, the second wave trap filters the interference of the signal output by the first wave trap, the third-stage amplifier receives the signal output by the second wavetrap, and the second emitter follower receives the signal output by the third-stage amplifier and outputs an amplified signal; and the power processing unit supplies power to the signal amplificationfilter unit. The small signal amplification device achieved by the invention is good in cost performance, high in signal-to-noise ratio and strong in portability.

A system and method are provided for isolating an input without adding significant distortion and without significantly adversely affecting the bandwidth of input circuits. In one embodiment, a single ended signal is substantially cancelled by an arrangement including an input resistance path in parallel with a negative resistance path wherein both paths substantially match in resistance. In another embodiment, a differential signal is substantially cancelled by a pseudo differential arrangement including two independent input resistance paths each in parallel with a corresponding negative resistance path, wherein the resistance paths substantially match the input resistance paths. In yet another embodiment, a differential signal is substantially cancelled by a differential arrangement including two resistance paths wherein a first negative resistance path is coupled between the first differential input and the second differential output and the second negative resistance path is coupled between the second input and the first output. In yet another embodiment, a current controlled current source may provide the negative amplification for the negative resistance path.

The embodiment of the invention provides a Zigbee module and electronic equipment, and relates to the field of communication. The Zigbee module comprises a main control chip which is used for processing a received data signal to obtain a transmitting signal; and a filtering circuit which is connected with the main control chip and is used for filtering the transmitting signal to obtain a filteredtransmitting signal, wherein the frequency of the filtered transmitting signal is kept within a preset range. The Zigbee module is good in transmitted signal quality, small in power loss and large intransmission distance.

The invention discloses a filtering device of a mobile data acquisition device. The filtering device comprises a first filtering circuit, wherein the first filtering circuit comprises a first operational amplifier, a first resistor R1, a second resistor R2, a first capacitor C1, a second capacitor C2 and a fourth capacitor C4; the first resistor R1 is serially connected with the second resistor R2, the other end of the end of the first resistor R1 that is connected with the second resistor R2 is a signal input end, and the other end of the end of the second resistor R2 that is connected with the first resistor R1 is connected with the inverting input end of the first operational amplifier; one end of the second capacitor C2 is connected to a circuit on which the first resistor R1 is connected with the second resistor R2, and the other end of the second capacitor C2 is connected with the output end of the first operational amplifier. According to the filtering device disclosed by the invention, the capacitors are connected to the connection line between a power supply and the first operational amplifier so as to ensure that a filter has no overshoot, is short in reducing time, and is reasonable in each frequency attenuation that is higher than the data rate; and the magnitude-frequency characteristics in transmission bands are stable, transition bands with suitable length can also be provided, and distortion cannot be easily caused.

The invention discloses a multilevel hybrid filtering circuit and method for under-well engineering parameter measurement signals. The circuit comprises an under-well measurement unit, a hybrid filtering unit, a post-processing unit and a power management unit. The under-well measurement unit is connected with the post-processing unit through the hybrid filtering unit. The power management unit is connected with the under-well measurement unit, the hybrid filtering unit and the post-processing unit. According to the multilevel hybrid filtering circuit and method for the under-well engineering parameter measurement signals provided by the invention, high frequencies and strong noises existing in weak small signals are filtered in a passive filtering mode; the signals are amplified according to certain multiples; precise band filtering is carried out through adoption of a second-order active filtering network; the signals are denoised in a passive-amplification-active hybrid filtering mode. The later signal processing, analysis and decision are carried out successfully. Compared with a general filtering mode, the circuit and the method have the advantage of improving the precision, accuracy and interference resistance of the under-well measurement data.

The invention provides a high-frequency heat sealing machine adjustable in strength. The high-frequency heat sealing machine comprises a machine body, an operation platform and a high-frequency control cabinet, and further comprises a heating frame, the heating frame is arranged above the operation platform through an installation frame capable of moving up and down, the heating frame is connectedwith an electric heating device, and the bottom of the heating frame is connected with a compression plastics mold. The high-frequency heat sealing machine further comprises an air cylinder and a pedal driving device, wherein the air cylinder is installed on the machine frame, a telescopic rod of the air cylinder is arranged vertically downwards, the heating frame is arranged under the telescopicrod of the air cylinder, the telescopic rod of the air cylinder can move downwards to push the installation frame to move downwards, the machine body is provided with an air cylinder start button, and the air cylinder start button is connected with the air cylinder; and the pedal driving device is connected with the installation frame and used for driving the installation frame to move up and down through feet of manpower. The bottom of the machine body is further provided with a heating pedal switch which is electrically connected with the high-frequency control cabinet and the electric heating device. The high-frequency heat sealing machine can conveniently conduct heat sealing through different compression strengths.

The invention relates to a front end circuit of accelerometer and a processing method of acceleration signal. The front end circuit is used to connect an acceleration sensor to obtain an original analog signal, and performing front end processing on the original analog signal. The front end circuit comprises: an amplifying circuit, which configured to be connected to the acceleration sensor to receive the original analog signal, and amplify the original analog signal; a low-pass filter circuit, which connected to the amplifying circuit for performing low-pass filtering processing on the amplified signal to eliminate noise. The amplifying circuit comprises: a first chopper circuit, which configured to be connected to the acceleration sensor to receive the original analog signal, and performa first chopping process on the original analog signal; an operational amplifier circuit, which connected to the first chopper circuit to amplify the output signal of the first chopper circuit; a second chopper circuit, which connected to the operational amplifier circuit to perform the second chopping process on the amplified signal. The noise in the front end circuit is small.

The invention provides a microwave resonance amplifying device and system, and relates to the technical field of signal processing devices. According to the microwave resonant amplifying device in theembodiment of the invention, an input signal is firstly amplified by an amplifier and is subjected to resonant amplification of a resonator, so that the microwave resonance amplifying device can obtain close gains at high and low frequency. The signal processed by the microwave resonance amplifying device can have a higher gain, and the microwave resonance amplifying device has better out-of-bandrejection characteristics. When a printed circuit board is designed, it is not necessary to consider the influence of the insertion loss on the system noise system, and it is not necessary to designa peripheral circuit, so that the design structure can be simpler, the design process can be simpler, the design efficiency can be improved, and the occupied area of the circuit board is smaller.

The invention discloses a filter circuit for a relaxation oscillator capable of effectively preventing comparator misjudgment. Compared with a comparator in a conventional relaxation structure oscillator, the filter circuit for the relaxation oscillator capable of effectively preventing comparator misjudgment provided by the invention performs filtering processing on the working process of the comparator, and can effectively filter out the misjudgment to the comparator due to the surge influence, so that the oscillator works more stably and reliably.

Some embodiments of the present application provide a filter circuit and chip based on MOS field effect transistors. The filter circuit includes a first MOS field effect transistor and an electrostatic discharge unit; during normal operation, a filter capacitor is formed between the gate of the first MOS field effect transistor and the substrate; when an ESD event occurs, the electrostatic discharge unit and the first A MOS field effect transistor forms a discharge path that transfers the accumulated electrostatic charge to ground. In the embodiment of the present application, on the basis of the first MOS field effect transistor, an electrostatic discharge unit is added, so that the capacitance characteristics and the characteristics of the ESD discharge path required between the power supply and the ground are combined in the same circuit, so that the circuit can be used in the same circuit. It exhibits capacitive characteristics during normal operation; when an ESD event occurs between the power supply and ground, it provides an ESD discharge path to play the role of ESD protection, thereby improving the ESD capability of the chip.

A wideband low power active isolator that may operate with a low voltage supply and provide improved linearity and insertion loss is described. The active isolator includes parallel connected common gate amplifier and common drain amplifier that are implemented using active transistors. A RF choke configured to suppress RF signal is coupled between input to the common gate amplifier and the ground such that the common gate amplifier also functions as a current source biasing the common drain amplifier.

The invention provides a microwave isolator which can solve the technical problems that a conventional ferrite microwave isolator is complex in structure, large in size, low in reliability, narrow inuse frequency range and incapable of meeting requirements. The microwave isolator comprises a preceding-stage attenuation network, a non-reciprocal semiconductor device and a post-stage attenuation network, the preceding-stage attenuation network serves as an input stage of the isolator and is connected with the preceding-stage link; the post-stage attenuation network serves as an output stage ofthe isolator and is connected with the post-stage link; a radio frequency link formed from the input stage to the output stage is a transmission channel; electromagnetic shielding structures are arranged between the input/output ends of the non-reciprocal semiconductor device and on the two sides of a radio frequency link formed from the isolator input stage to the isolator output stage. A semiconductor device is adopted, the product working frequency range is wide, the relative bandwidth is also wide, and the application range is wider; the working frequency range of the microwave isolator isalmost not limited and can cover DC-terahertz, and as long as the semiconductor chip supports how high the working frequency, the semiconductor chip can be suitable for how high the frequency range.

The invention relates to a filtering detection liner compression-resistant metal hose cutting integral device. By connecting liner supports (1) with metal hoses (8) of various diameters in a one-to-one correspondence mode through an electrically control telescopic rod (6), in combination with fixing arrangement of the electrically control telescopic rod (6) and a position clamping device (7) for fixing the metal hoses (8), moving of the liner supports (1) in the metal hoses (8) with the corresponding diameters is achieved; based on the interval, matched with the thickness of a cutterhead body of an electrically control rotary cutterhead (5), between two cylinders in each liner support (1), in combination with real-time capture of the position of the cutterhead body of the electrically control rotary cutterhead (5) between the two corresponding cylinders through a distance measurement sensor (16), intelligent control over cutter plunging, return and secondary cutter plunging of the electrically control rotary cutterhead (5) is achieved, cutting of the metal hoses (8) is achieved, the one-click operation of the whole process is achieved, and the deformation problem of cut ends can be effectively avoided while the cutting working efficiency of the metal hoses (8) is ensured.