Abstract: An amplifier includes an input circuit, an amplification circuit, and at least two feedback circuits. The input circuit is connected with an input end of the amplification circuit; an output end of the amplification circuit is connected with a first end of each of the feedback circuits respectively; a second end of each of the feedback circuits is connected with the input circuit respectively. The input circuit is configured to receive an input signal and a feedback signal; the amplification circuit is configured to amplify the input signal and the feedback signal to obtain an amplified signal. The feedback signal is fed back to the input circuit by feeding back at least a part of the amplified signal through a target feedback circuit; and the target feedback circuit is a feedback circuit that depends on the type of the input signal of the at least two feedback circuits.

Abstract: A power amplifier circuit includes a power amplification circuit and a diode assembly. The diode assembly is connected in series with a transistor amplification circuit of the power amplification circuit, and the transistor amplification circuit is configured to, when load of power amplifier is mismatched, turn the diode assembly on, so as to divide current voltage to at least two electrodes of the transistor amplification circuit.

Abstract: A power amplifier includes a current generating circuit, a first mirroring circuit, a power amplifying circuit and a stacked circuit, in which the current generating circuit is configured to output a first current according to a received first control voltage; the first mirroring circuit is configured to, according to the first current, minor the current and output a first bias current, the first bias current for being input into the power amplifying circuit; and the power amplifying circuit is configured to, according to a first radio frequency signal and the first bias current, output a second radio frequency signal with a power that meets a preset condition.

Abstract: A movable system for automatically monitoring the correlated wind and temperature filed of a bridge, including a bridge monitoring subsystem, a cloud server, and a client. The system monitors the meteorological parameters of a bridge surface and a temperature of a bridge structure, performs data analysis and processing on a cloud server, and performs visual data interaction by using a client. A bridge surface-specific meteorological parameter monitoring module is movable, such that the location of the sensor for meteorological data monitoring can be adjusted at any time to monitor an entire bridge deck in a time-sharing manner. A lower cantilever structure has an adjustable height, such that the sensor for meteorological data monitoring can track a height of a boundary layer of the bridge surface. A bridge structure-specific temperature monitoring module adopts distributed patch-type temperature sensors, which can detect the temperature of the bridge structure in all directions.

Abstract: Disclosed is an angle-adjustable three-dimensional physical simulation device for equivalent coal seam mining, which comprises a base, a frame, a loading frame, an angle-adjusting device, a limiting plate and a lifting combined module. The top of the base is fixedly connected with the frame; the top of the frame is fixedly connected with the loading frame; the angle-adjusting device is located between the base and the frame; the bottom of the frame is fixedly connected with the limiting plate; the limiting plate is penetrated with a lifting combined module; the lifting combined module comprises a plurality of lifting pieces, and the lifting pieces comprise bolts and cushion blocks; the bolt penetrates through the limiting plate and is in threaded connection with the limiting plate; and one end in the bolt frame is rotatably connected with the cushion block.

Abstract: A movable system for automatically monitoring the correlated wind and temperature filed of a bridge, including a bridge monitoring subsystem, a cloud server, and a client. The system monitors the meteorological parameters of a bridge surface and a temperature of a bridge structure, performs data analysis and processing on a cloud server, and performs visual data interaction by using a client. A bridge surface-specific meteorological parameter monitoring module is movable, such that the location of the sensor for meteorological data monitoring can be adjusted at any time to monitor an entire bridge deck in a time-sharing manner. A lower cantilever structure has an adjustable height, such that the sensor for meteorological data monitoring can track a height of a boundary layer of the bridge surface. A bridge structure-specific temperature monitoring module adopts distributed patch-type temperature sensors, which can detect the temperature of the bridge structure in all directions.

Abstract: A temperature compensation circuit is configured to generate a first electrical signal corresponding to the current ambient temperature, use the first electrical signal to adjust a second electrical signal received by an electrical signal input end, and obtain a third electrical signal; and output the third electrical signal to a power control circuit. The power control circuit is configured to convert the third electrical signal into a fourth electrical signal and output the fourth electrical signal to a power amplifier. The fourth electrical signal is used for controlling the gain of the power amplifier to present a preset change rule following a temperature change. Thus, by adding the described temperature compensation circuit in a power amplification circuit, the stability of the gain and the stability of the output power of a power amplifier are ensured, and the performance of the power amplifier is not affected by a change in temperature.

Abstract: When a signal source sends a radio-frequency signal to an input amplification circuit, a control circuit sends a first control signal to the input amplification circuit according to the frequency of the radio-frequency signal, the input amplification circuit receives the first control signal and forms an input oscillation loop, the radio-frequency signal forms an amplified first signal through the input oscillation loop, and the input amplification circuit sends the first signal to the output amplification circuit. According to the frequency of the radio-frequency signal, the control circuit transmits a second control signal to the output amplification circuit, which forms an output oscillation loop matched with the first signal. The first signal is amplified by the output oscillation loop to form an emitting signal, the output amplification circuit transmits the emitting signal to the emitting antenna for emitting, thereby improving the utilization ratio of a radio-frequency front end chip package.

Abstract: A bias circuit includes a mirror current source and a current-to-voltage converter. A first terminal of the mirror current source is connected to a supply voltage terminal, a second terminal of the mirror current source is connected to a reference voltage terminal, and a third terminal of the mirror current source is connected to the current-to-voltage converter. A mirror current source is configured to acquire a supply voltage transmitted at the supply voltage terminal through the first terminal, acquire a reference voltage transmitted at the reference voltage terminal through the second terminal, and regulate the supply voltage by using the reference voltage and a preset parameter to obtain a mirror current corresponding to the supply voltage. The preset parameter is parameter information of the mirror current source. The current-to-voltage converter is configured to convert the mirror current into a voltage to provide a bias voltage based on the voltage.

Abstract: A power amplifier circuit includes a power amplification circuit and a diode assembly. The diode assembly is connected in series with a transistor amplification circuit of the power amplification circuit, and the transistor amplification circuit is configured to, when load of power amplifier is mismatched, turn the diode assembly on, so as to divide current voltage to at least two electrodes of the transistor amplification circuit.

Abstract: An amplifier includes an input circuit, an amplification circuit, and at least two feedback circuits. The input circuit is connected with an input end of the amplification circuit; an output end of the amplification circuit is connected with a first end of each of the feedback circuits respectively; a second end of each of the feedback circuits is connected with the input circuit respectively. The input circuit is configured to receive an input signal and a feedback signal; the amplification circuit is configured to amplify the input signal and the feedback signal to obtain an amplified signal. The feedback signal is fed back to the input circuit by feeding back at least a part of the amplified signal through a target feedback circuit; and the target feedback circuit is a feedback circuit that depends on the type of the input signal of the at least two feedback circuits.

Abstract: A bias circuit includes a first branch circuit, a second branch circuit, a current amplifier and a switch, wherein the first branch circuit is configured to shunt an inputted first current, and input a first branch current of the first current to a power supply ground; the second branch circuit is configured to shunt the inputted first current, and input a second branch current of the first current to the current amplifier; the current amplifier is configured to receive the second branch current of the first current and amplify the second branch current of the first current to serve as a bias current of a power amplifier connected to the bias circuit for outputting; and the switch is configured to switch different resistance values for a resistor in the first branch circuit and/or switch different resistance values for a resistor in the second branch circuit.

Abstract: A signal transceiving control structure includes a power amplifier and N control branches. The N control branches are configured to control transmission of first signals or receiving of second signals of different network standards according to different control instructions. First ends of the N control branches are respectively connected to an output end of the power amplifier, second ends of the N control branches are respectively connected to N external output ends, third ends of the N control branches are respectively connected to N external input/output ends, wherein N is a positive integer greater than 1. The power amplifier is configured to perform power amplification on the first signals.

Abstract: A bias circuit includes a first branch circuit, a second branch circuit, a current amplifier and a switch, wherein the first branch circuit is configured to shunt an inputted first current, and input a first branch current of the first current to a power supply ground; the second branch circuit is configured to shunt the inputted first current, and input a second branch current of the first current to the current amplifier; the current amplifier is configured to receive the second branch current of the first current and amplify the second branch current of the first current to serve as a bias current of a power amplifier connected to the bias circuit for outputting; and the switch is configured to switch different resistance values for a resistor in the first branch circuit and/or switch different resistance values for a resistor in the second branch circuit.

Abstract: A signal transceiving control structure includes a power amplifier and N control branches. The N control branches are configured to control transmission of first signals or receiving of second signals of different network standards according to different control instructions. First ends of the N control branches are respectively connected to an output end of the power amplifier, second ends of the N control branches are respectively connected to N external output ends, third ends of the N control branches are respectively connected to N external input/output ends, wherein N is a positive integer greater than 1. The power amplifier is configured to perform power amplification on the first signals.