41results about How to "Increase the carrier frequency" patented technology

A controller controls switching of IGBT devices of an inverter according to the desired output of the permanent magnet motor. The controller includes: a magnet temperature detection device that detects the magnet temperature of the permanent magnet motor based on the output of a temperature sensor; a setting device that sets a threshold value of the magnet temperature corresponding to the desired output of the permanent magnet motor, based on a predetermined relation between the output from the permanent magnet motor and a critical temperature, up to which demagnetization in the permanent magnet motor is not caused; and a carrier frequency control device that, when the magnet temperature detected by the magnet temperature detection device exceeds the threshold value, changes the carrier frequency, at which the IGBT devices are switched, such that a ripple current superimposed on a motor current that flows through the permanent magnet motor is reduced.

The invention discloses an SDR-based agile multi-mode multi-channel transceiver. The SDR-based agile multi-mode multi-channel transceiver includes a host computer, a display unit, a PCI bus data transceiver unit, an FPGA digital signal generation and reception demodulation analysis module, and an agile multi-mode multi-channel transceiver module. Among them, the FPGA digital signal generation and reception demodulation analysis module is used to realize multi-mode and multi-style signal generation and reception demodulation analysis functions, and the agile multi-mode multi-channel transceiver module is used to realize multi-signal mode and multi-communication style signal multi-channel RF transceiver function. The device in the present invention can support wireless communication signal sending and receiving scenarios such as general-purpose software-defined radio applications, MIMO radio, and wireless communication base stations, and has high integration, high consistency, high carrier frequency and bandwidth, multiple signal communication styles, and multiple signal formats. Support multi-input multi-output and other advantages.

The present invention includes method and apparatus for converting optical signals to MWOF signals for transmission to wireless data, audio and / or video terminals in the W-band. Advantageously, there is no need to maintain expensive and complex remote stations because a centralized station performs all the complex processing.

This electromagnetic switching-valve position detection system is provided with: a current control circuit that obtains a smoothed direct current by smoothing a current from a power source via a rectifier bridge diode and a primary-side smoothing capacitor, that transmits the direct current to the secondary side by a switching transformer as an alternating current of pulse waves from a switching element where switching is controlled in accordance with a pulse signal from a pulse signal generation device, and that outputs same as a direct current that has been smoothed via a secondary-side diode and a secondary-side capacitor; a carrier wave generation device for superimposing high-frequency carrier waves for position detection onto signal waves of a current command; and a detection unit for extracting a frequency component of the carrier waves from a voltage feedback signal of a solenoid, and detecting a voltage amplitude thereof to obtain an amplitude signal. A control unit further comprises: a position determination unit for determining a valve spool position on the basis of the amplitude signal and preset criterion reference values corresponding to respective valve spool positions, and outputting a determination signal; and a determination circuit for outputting a valve position signal on the basis of the determination signal.

The invention relates to the technical field of mobile communication, and discloses a tunnel leaky cable communication system, that is, a main unit device that outputs a multi-channel intermediate frequency modulation signal in the source part, and then uses the leaky cable to transmit the intermediate frequency modulation signal and radiates to Space in the tunnel, and then use the vehicle-mounted relay unit equipment placed on the car body of the train running in the tunnel to convert the intermediate frequency modulation signal into a multi-channel radio frequency carrier signal at a target operating frequency higher than the cut-off frequency of the leaky cable, covering To the interior of the carriage, not only does it not need to redeploy new leaky cables that support higher cut-off frequencies, it greatly reduces the deployment cost, construction cost and difficulty of leaky cable coverage solutions for mobile communication signals with higher carrier frequencies (especially 5G signals), and supports Multi-channel communication; on the other hand, the system synchronization and equipment management of the on-board relay unit equipment are carried out by using cooperative base stations, which ensures the robustness of the on-board relay unit equipment.

The present invention provides a ground user navigation and positioning method based on the Beidou Ka inter-satellite link signal, comprising the following steps: (1) assuming that between k-1 and k two epochs, where k=1,2,3, ..., users equipped with Beidou inter-satellite link signal receiving terminals in a certain area on the ground generate inter-satellite link one-way ranging values ​​with N different Beidou satellites at different times, thereby obtaining N ranging equations; (2) using the receiving The machine clock model and inertial navigation information will uniformly reduce the user position in the ranging equation to T k (3) On the basis of realizing the time synchronization of the ranging value, ground users use the Kalman filter positioning algorithm to estimate their position in real time. The invention can avoid the interference source and deception source for the L-band navigation signal, compensate the usability problem caused by the failure of the L-band navigation signal to a certain extent, and ensure the navigation safety of key areas in special scenarios.

The invention provides a SVPWM modulation method, device and system. Wherein the SVPWM modulation method includes the steps: using the voltage U α_n , U β_n Determine the sector where the voltage vector of the three-phase motor is located, in which the voltage U in the two-phase stationary coordinate system is affected by the bus voltage α , U β Perform per unitization to get the voltage U α_n , U β_n ;Through the voltage U α_n , U β_n , determine the action time of each phase of the voltage vector in each sector; calculate the duty cycle of each phase of the voltage vector in PWM according to the action time of each phase of the voltage vector, and obtain the PWM wave for controlling the three-phase motor. The SVPWM modulation method proposed by the present invention can directly calculate the conduction time of each phase in the three-phase PWM wave, without first calculating the conduction time Tk and Tk corresponding to the two adjacent basic vectors Vk and Vk+1 in the sector area. Tk+1 and the switching time T0 corresponding to the zero vector, and then time allocation and reconstruction, greatly reduce the running time of the SVPWM algorithm.

The invention relates to a wide-band linear frequency modulation continuous millimeter-wave signal emitting source of a line patrol obstacle avoidance radar of an unmanned aerial vehicle. The output end of a constant temperature crystal oscillator is connected with a DDS reference signal source and a phase locked dielectric resonator oscillator, and the DDS reference signal source is connected with a control system; the DDS reference signal source is connected with a first filter, a phase locker, a low-pass filter, a voltage-controlled oscillator, a three-power distributor, a frequency multiplier, a first power amplifier and an antenna in sequence; the phase locked dielectric resonator oscillator is connected with a frequency mixer, the output of the frequency mixer is divided into two passages, and one passage is connected with a second filter, a first amplifier and the phase locker; the other passage is connected with the three-power distributor; the three-power distributor is further connected with a receiver to perform equal-energy power distribution; the frequency multiplier multiplies the received signal into 8-millimeter wave band signal, and the signal is emitted through the antenna after being amplified. The wide-band linear frequency modulation continuous millimeter-wave signal emitting source of the line patrol obstacle avoidance radar of the unmanned aerial vehicle is mainly used for a line patrol system of the unmanned aerial vehicle for a power transmission line, is capable of realizing the obstacle avoidance detection (the obstacle comprises a tower, the power transmission line and so on) for the unmanned aerial vehicle, and enables the detection target distance resolution ratio to be improved.

The invention provides a method and a device for generating X-frequency band one-way ranging signals for deep space exploration. The method provided by the invention can generate one-way ranging sidetone signals in the X-frequency band. The device provided by the invention comprises simulation devices such as a crystal oscillator, a frequency divider, a low-pass filter, a frequency multiplier, a phase shifter and the like, and turn-off of DOR (Differential One-way Ranging) sidetone signals can be controlled through an instruction. The crystal oscillator generates initial reference signals, one path of the initial reference signals are inputted into the frequency multiplier after power division, the frequency multiplier generates X-frequency band carriers, another path of the initial reference signals are inputted into a divide-by-two frequency divider, a left path of the initial reference signals are inputted into a divide-by-ten frequency divider, and two paths of DOR sidetone signals are generated respectively. Phase modulation is carried out on the two paths of DOR sidetone signals in the X-frequency band, and the two paths of DOR sidetone signals are outputted after being amplified and isolated. Divide-by-two frequency division and divide-by-ten frequency division are completed by a decimal counter. The X-frequency band one-way ranging signals generated by using the method provided by the invention can complete a function of accurate ranging for a deep space probe by being matched with relevant ground station equipment, thereby being applicable to the fields of lunar exploration, Mars exploration and the like.