177 results about "Reverse isolation" patented technology

A radio receiver is described that processes multiple wireless standards using a single antenna according to embodiments of the invention. The radio receiver includes a single antenna, and a low noise amplifier that is connected to the antenna, without an intervening power divider or power splitter. The output of the low noise amplifier feeds multiple wireless receivers in a parallel arrangement that are operating according to different communications standards, including for example a Bluetooth and a WLAN 802.11. Additional wireless standards and their corresponding receivers could be added as well. The input impedance of the low noise amplifier defines the impedance seen by the antenna, regardless of which operational standard is actually in use. Each signal path includes an additional low noise amplifier having a gain that can be customized for the particular signal path and receiver in use, and which also improves the reverse isolation between signal paths. Further, a switch can be added to one or more of the signal paths so as to further improve isolation when a particular path is not being used.

The invention discloses a broadband low noise amplifier which comprises a primary common source and common gate amplifying circuit, a secondary common source amplifying circuit, an input and output matching circuit for providing a high gain for the circuit, a current extraction circuit for reducing the noise factor of the circuit, an MOS tube current source bias circuit, an HBT bias circuit and a bias network filter circuit for further reducing the noise factor of the circuit, wherein the common source and common gate circuit provides the high gain and simultaneously increases the reverse isolation degree of the circuit, and the common source amplifying circuit further improves the gain of the circuit; the MOS bias circuit and the HBT bias circuit provide stable low noise bias for a common gate tube and a common source tube; and the bias filter circuit filters radio-frequency signals on the bias to stabilize the bias, thereby reducing the noise factor to the minimum. The invention can be widely applied to modern wireless communication standards such as GSM850, GSM900, DCS1800, PCS1900, WCDMA and the like.

Continuous variable-gain low-noise amplifier. The amplifier continuously adjusts its gain between well-defined high and low values by using a cascode current-steering circuit to partition signal current between two different nodes of an output loading network. A shunt feedback network connected from an intermediate node of the loading network to the input provides negative feedback that linearizes the amplifier as its gain is decreased. The circuit degrades the noise figure at lower gains by varying the gain without directly dumping the signal current to the power supply. The circuit produces only small changes in input and output impedances and preserves an improved reverse-isolation cascode characteristic as the gain is controlled.

The invention provides a power amplifier with an adjustable output power, which comprises a main power amplifier (1) and a matching network circuit (2). The output end of the main power amplifier (1) is connected with the input end of the matching network circuit (2). The switch control power amplifier and a neutralizing capacitor technique are adopted, and the two ends of one switch array (11) of the main power amplifier (1) are respectively connected between the ground and the power amplifier; and the two ends of the other switch array (12) of the main power amplifier (1) are respectively connected between a power supply and the power amplifier, the switch control power amplifier is enabled to be better compatible with the neutralizing capacitor technique and the reverse isolation degree and the stability are improved. Besides, since the matching network circuit (2) with variable capacitors is adopted, by adjusting capacitors (6 and 7), the impedance conversion rate can be adjusted and a capacitor (5) is adjusted at the same time to enable the circuit resonance frequency to reach set frequency. The power amplifier with adjustable output power can meet the need of multi-power output in the existing power transmitting technique, the stability and the reverse isolation degree of the multi-power output are improved and the efficiency during power back-off is improved.

The present patent application comprises a linear transconductor having at least one input and at least one output, comprising a differential amplifier having a plurality of transistors and a plurality of inputs, wherein a difference of input signals is amplified, a cascode circuit having a plurality of transistors, wherein the transistors are operably connected to the differential amplifier, wherein reverse isolation between an input and an output of the linear transconductor is improved by decoupling the input and the output of the linear transconductor by mounting at least one transistor of the plurality of transistors of the cascode circuit as a common-gate stacked on the at least one transistor of the differential amplifier, an active load having a plurality of transistors operably connected between the cascode circuit and supply voltage, and an auxiliary device operably connected to the connection between the active load, the cascode device and ground.

The invention discloses a single-ended input and differential output parallel dual-frequency low noise amplifier (LNA) and a design method thereof. The LNA can be applied to a digital TV, wireless communication and a navigation receiver and mainly comprises an input matching network, a main amplification circuit, an output network and a single-ended to differential circuit. The main amplification circuit adopts a cascode structure and has favorable reverse isolation degree; the input matching network enables the LNA to realize impedance matching and noise matching simultaneously in input stage and dual frequency ranges, and thus the noise performance of the circuit is improved at the same time of ensuring the maximum power transmission; and the singled-ended to differential circuit ensures that the LNA can be directly cascaded with a front-end antenna and a rear-end mixer circuit and easy to integrate. The LNA disclosed by the invention not only has a simple design, but also ensures that the system power consumption and area are reduced due to parallel dual-frequency receiving.

The invention discloses a cross-regional data security efficient interaction system and method for a monitoring platform of an electric power communication network, and solves the problems that cross-regional data interaction of the monitoring platform of the electric power communication network has potential safety hazards, the efficiency is not high and the time delay is high. The system comprises a monitoring information acquisition module, a monitoring application module and an isolation device, the monitoring information acquisition module is used for acquiring operation data of each network manager and transmitting the acquired data to the monitoring application module for each service module to use; the isolation device comprises a forward isolation device and a reverse isolation device, the forward isolation device is used for realizing one-way transmission of data from the monitoring information acquisition module to the monitoring application module, and the reverse isolationdevice is used for realizing one-way transmission of data from the monitoring application module to the monitoring information acquisition module; and the monitoring application module is used for receiving the data sent by the monitoring information acquisition module, performing storage and analysis processing, and reversely sending a request task to the monitoring information acquisition module.

The invention relates to an optical fiber beam combiner and a preparation method thereof, and the technical problem that reverse isolation performance for protection of a pump laser is poor is solved. The optical fiber beam combiner is composed of an input multimode fiber, an input signal optical fiber and an output optical fiber. After fused biconical tapering is carried out on a bare fiber of the input multimode fiber and a bare fiber of the input signal optical fiber to some extent, the bare fiber of the input multimode fiber and the bare fiber of the input signal optical fiber are perpendicularly cut from the middle to be connected with a bare fiber of the output optical fiber in a fused mode. The input signal optical fiber is an optical fiber having a cladding is formed by random optical fibers with claddings in a fused connection mode. The optical fiber beam combiner of the structure has excellent reverse isolation performance, well protects the pump laser, is especially applied to a high-power fiber laser and an optical fiber amplifier, and has the advantages of being simple in manufacturing process, high in coupling efficiency, stable in performance and the like.

The invention discloses a wind power prediction system for a wind power plant. The wind power prediction system focuses on the actual applications of the wind power plant, combines specific requirements in the aspects of actually-measured data, prediction power amendment and report, safety and the like, and comprises five parts of an anemometer tower, an SCADA fan data monitoring device, an external network server, a reverse isolation device, an internal network server, wherein the anemometer tower and the SCADA fan data monitoring device are connected to the external network server by a data transmission line, and the external network server is connected with the internal network server by the reverse isolation device on the basis of the safety of the wind power plant; a data acquisition function unit and an SQL acquisition database are installed on the external network server, and a power prediction function unit and an SQL prediction database are installed on the internal network server. The system supports user level and permission settings, all the data is stored in the databases, all forms and curves are provided with the functions of printing output and spreadsheet output simultaneously, and various prediction models are embedded, and the prediction accuracy can be increased by selecting the different prediction models in different wind power plants or different seasons.

The invention discloses a load balanced and high-reliability data transmission method across forward and reverse isolation. Internal and external network data distribution modules are arranged betweeninternal and external network data transmission modules and forward and reverse isolation devices. Double links are established between the internal and external network data distribution modules andthe forward and reverse isolation devices respectively for processing and distributing the internal and external network data and balancing the load. Thus the data transmission efficiency is greatlyimproved. The health status of the links are also detected by the internal and external network data distribution modules in real time, and faulty links are avoided. Thus the safety and reliability ofdata transmission are improved.

The invention discloses a variable gain low-noise driving amplifier. The amplifier has a fully differential cascode structure, wherein a common gate consists of three side-by-side silicon germanide bipolar transistors; the central silicon germanide bipolar transistor adopts parallel capacitive feedback, a reasonable input/output matching circuit is adopted, a high variable gain is provided for a circuit, and the noise coefficient is reduced; a cascade circuit provides a high variable gain and increases the reverse isolation of the circuit at the same time; and a common source amplifying circuit further improves the gain of the circuit. By controlling the selection of an external bias, the variable gain with a 3dB step length is obtained. The variable gain low-noise driving amplifier has the characteristics of high variable gain, low noise and low power consumption.

The invention discloses an electric leakage prevention plug circuit which comprises an indicating lamp circuit, a null wire, a ground wire, a live wire, a buckle releasing device, a rectifying circuit, a step-down circuit, a reverse isolation circuit, an overtemperature detection circuit, a testing circuit, a first resistor, a first magnetic induction loop, a first amplifying circuit, controllable silicon, a second magnetic induction loop, a third magnetic induction loop and a second amplifying circuit. According to the electric leakage prevention plug circuit, the type of a needed mutual inductor can be chosen through a change-over switch, and the defect of mistrip caused by the charged null wire is overcome.

The invention discloses an analog front-end circuit for a fully-differential optical receiver based on an adjustable common-emitter common-base structure. The analog front-end circuit comprises two photoelectric detectors, a set of cascade differential amplitude-limiting amplifiers and an output buffer stage, wherein the structures of the two photoelectric detectors are completely symmetrical; the analog front-end circuit further comprises a differential structure adjustable common-emitter common-base trans-impedance amplifier and a first-stage common-emitter amplifier; the trans-impedance amplifier comprises a common-emitter common-base structural amplifier; a resistor and capacitor parallel manner is adopted in a tail current source; the first-stage common-emitter amplifier comprises a common-emitter amplifier and a degenerate resistor and capacitor for improving the reverse isolation degree of the circuit; furthermore, a low-frequency pole is compensated through a capacitive degeneration technology; the differential amplitude-limiting amplifiers are used for changing resistance feedback in a Cherry-Hooper structure into active feedback; furthermore, an output load resistor is additionally arranged; the output buffer stage is used for converting output impedance into 50-omega standard impedance; and thus, the driving capability is improved. The analog front-end circuit for the optical receiver having excellent performance is researched in the invention.

The invention provides a load balancing method based on the combined application of reverse isolation devices and an isolation gateway. The load balancing method comprises the following steps of: operating an agent program on file servers of the reverse isolation devices, and respectively establishing transmission control protocol (TCP) connection between each file server and the isolation gateway; detecting the health condition of a link where each reverse isolation device is located by using a TCP-based private health detection mechanism; and allocating reverse service data according to the health condition of the link where each reverse isolation device is located. According to a technology, the isolation gateway performs service availability detection on servers in front of isolation devices; and when the buffered service data of each server are overloaded or the self state of each server fails, the isolation gateway sends a response message according to the received detection message to determine the health condition of the current link, and performs load balancing according to the health condition. The method is high in load balancing efficiency, the deployment of a bandwidth expansion and network safety scene is realized, and requirements on high safety, high bandwidth and high reliability of the combination of the reverse isolation devices and the isolation gateway are met.

The invention discloses a method and system for processing relay protection definite value data. The method comprises the steps that first relay protection definite value data are obtained from a definite value database located in a safety area III according to the preset period; an instruction is called to upload the first relay protection definite value data to a transmission sensor in the safety area III; the transmission sensor packages the received first relay protection definite value data to generate second relay protection definite value data, and transmits the second relay protection definite value data to a reverse isolation device; the reverse isolation device verifies the received second relay protection definite value data, if verification fails, the follow-up steps stop executing, and if verification is successful, the second relay protection definite value data are pushed to a checking server in a safety area II. Compared with the prior art, the method for processing the relay protection definite value data solves the problem that time delay is caused due to manual copying and transfer of the relay protection definite value data, and timeliness of checking and updating of the relay protection definite value data is improved.

The invention relates to a one-key sequential control double-confirmation system and method based on disconnecting switch position intelligent identification. A sequential control monitoring host confirms the isolation switch needing sequential control operation, and transmits the serial number and the on-off state of the isolation switch needing to be operated to a video monitoring host; the video monitoring host calls a corresponding preset position of the camera according to the serial number of the isolating switch, acquires a real-time video, sends the video to an intelligent analysis host for analysis, and writes an analysis result is written into a file in an e format; a judgment result file is transmitted to the sequential control monitoring host through a reverse isolation device,and the sequential control monitoring host analyzes the result file to obtain an isolation switch position and remote signaling for dual confirmation. One-key sequential control requires sequential control operation to obtain double confirmation of non-homologous signals, video image recognition is adopted as a second criterion, and the system has the advantages of being accurate in judgment, completely independent in installation, free of power failure, convenient to maintain, safe and reliable.

Two MOSFETs connected in common source mode are as input ends of the differential signal of amplifier. Resistance, inductance or other active device is adopted as load as well as feedback element at source end of amplifier or trail current source. Two MOSFETs identical to two input MOSFETs in common source mode are added. Gate end of one MOSFET is connected to gate end of input MOSFET for inputting positive signal; and drain end is connected to drain end of input MOSFET for inputting negative signal (negative output end). Gate end of the other MOSFET is connected to gate end of input MOSFET for inputting negative signal; and drain end is connected to drain end of input MOSFET for inputting positive signal (positive output end). The invention takes full advantage of identical gate-drain capacitances of MOSFET parts operated at saturation region and cutoff region. Features are: low voltage, low power consumption and high degree of reverse isolation.

The invention discloses a terahertz isolator based on a photonic crystal heterojunction. The terahertz isolator comprises the photonic crystal heterojunction which is composed of a first photonic crystal and a second photonic crystal and used for receiving incidence of terahertz waves, an incidence port used for leading in of the terahertz waves, and an exit port used for leading out of the terahertz waves, wherein the incidence port and the exit port are respectively arranged on the two sides of the photonic crystal heterojunction. The first photonic crystal and the second photonic crystal are respectively provided with a plurality of small holes and large holes. On the basis of the same period of the first photonic crystal and the second photonic crystal, the effect of transmission and isolation is achieved by controlling the radius ratio of the large holes to the small holes, the size of the incidence port, the size of the exit port and the interface shape, and high forward-direction transmittivity and high reverse isolation are achieved. The terahertz isolator based on the photonic crystal heterojunction can normally work under the normal temperature and normal state condition without the extreme condition such as low temperature and magnetic fields.

The invention relates to a wind power generator equipment safety production management system and an operation method thereof. The system comprises a safety first area and a safety third area. The safety first area and the safety third area are connected through an isolation device. The isolation device comprises a forward isolation net brake and a reverse isolation net brake. A two-ticket server is arranged in the safety third area. The reverse isolation net brake enables data of the two-ticket server to be returned to the safety first area from the safety third area, and a data sharing purpose is achieved. According to the invention, the reverse isolation device is added based on an original network structure, data sharing system of a two-ticket system is realized, and that is to say, two-ticket data can be checked respectively in different safety areas, so that the usage is facilitated for the working personnel.

There is disclosed an injection circuit for measuring radio frequency (RF) signals in an RF receiver for use in measuring the impedance match of a receive antenna and for use in calibrating receiver gain, wherein an advantageous embodiment of the injection circuit comprises: 1) a circulator coupled to the receive antenna; 2) a directional coupler coupled to the circulator; 3) an injection source coupled to the circulator and to the directional coupler, wherein the injection source is capable of injecting a test RF signal into either the circulator or the directional coupler; and 4) a terminating switch for selectively enabling or disabling the transfer of a test RF signal from the injection source to either the circulator or the directional coupler. The circulator has a reverse isolation of at least 20 dB that significantly increases the accuracy of the measurements of the RF signals compared with the accuracy that may be achieved by prior art methods. The present invention obtains the received signal strength indicator (RSSI) measurements at any instantaneous temperature and operating channel and determines voltage standing wave ratio (VSWR) measurements.

The invention discloses a method for monitoring the performance of exchange boards across safety subareas. The method includes receiving operation commands for configuring monitored exchange board equipment on safety areas III by the aid of an acquisition server; extracting operation commands required to be transmitted to safety areas II from the operation commands; transmitting the operation commands required to be transmitted to the safety areas II to an acquisition server for the safety areas II by a reverse isolation device. The method has the advantages that operation instruction files can be automatically transmitted across the safety subareas, and accordingly the work efficiency can be improved. The invention further discloses a system for monitoring the performance of the exchange boards across the safety subareas.