26 results about "Direct digital synthesizer" patented technology

The invention provides a vector signal source and a design method thereof, which can be applied to the technical field of communication. The vector signal source comprises: a generation module comprising a plurality of parallel direct digital synthesizers, the generation module being configured to generate a plurality of target digital signals based on drive clock signals corresponding to the plurality of direct digital synthesizers, the driving clock signals respectively corresponding to the plurality of direct digital synthesizers have phase differences relative to each other and are equal in frequency; the conversion module comprises a plurality of digital-to-analog converters electrically connected with the plurality of direct digital synthesizers respectively, and the conversion module is configured to convert the received multiple paths of target digital signals into multiple paths of target analog signals respectively based on sampling clock signals corresponding to the multiple digital-to-analog converters respectively, the sampling clock signals corresponding to the plurality of digital-to-analog converters are synchronized relative to each other; and the synthesis module is configured to integrate the multiple paths of target analog signals according to a time sequence to obtain a target vector signal source.

In one example, an RF oscillator system includes a laser source configured to emit laser light, a housing, a crystalline microresonator disposed within the housing, and a photonic integrated circuit disposed within the housing, the photonic integrated circuit including an optical waveguide network and configured to generate a clock signal based on the laser light. The RF oscillator system may further include at least one photonic wirebond configured to couple the laser light between the optical waveguide network and the crystalline microresonator via evanescent coupling; laser control circuitry disposed within the housing and configured to lock a frequency of the laser light to a resonance of the microresonator to generate the clock signal; and a direct digital synthesizer disposed within the housing and configured to produce a tunable oscillator signal based on the clock signal.

This high-frequency signal generation device is provided with: (A) a clock signal generation unit that generates a clock signal using a harmonic component generated by an amplifier having nonlinearity; (B) a direct digital synthesizer (DDS) that generates a frequency signal having a frequency set by the frequency setting data, using the clock signal as a system clock for operating the internal processing; and (C) a frequency-increasing unit that is configured from a non-active frequency multiplier that does not use an active element, and that increases the frequency of the frequency signal generated by the DDS. A clock signal is generated using a harmonic component generated by an amplifier having nonlinearity, and in a frequency variable function, a delay time is shortened to cope with a high speed, and spurious and phase noise are suppressed to cope with a high C / N ratio.

The invention relates to the technical field of automotive electronics and communication, and provides a DDS (Direct Digital Synthesizer)-based safety vehicle-mounted communication method, which comprises the following steps of: dividing whole vehicle data into non-safety data, periodic safety data and non-periodic safety data; establishing a communication channel for each type of data; for a non-periodic transmission channel, a special protection scheme is adopted, and a communication failure mode is detected: a sender configures a life cycle for data, and after the data is sent, the life cycle is monitored; when the data is discarded due to exceeding the life cycle, the sender updates the life overrun state; the receiver replies based on an ACK / NACK mechanism, and the sender updates the service life overrun state when the time is out and the confirmation is not carried out; arranging a monitor at a receiver, and detecting a communication failure event of data loss when the monitor monitors a service life overrun state; when a communication failure is detected, the communication management middleware notifies the security application. The invention aims to solve the problems that data protection is not distinguished and non-periodic data cannot be effectively detected in an existing scheme.

The present application relates to a kind of multi-mode noise interference signal generation method, belong to signal interference technical field, solve the problem that existing cannot dynamically flexibly generate the interference signal of multiple modulation modes and the high development complexity.For method includes: according to noise kind and interference mode, obtain first noise sequence, second noise sequence, third noise sequence, noise interference bandwidth and center frequency;Carrier signal is generated based on center frequency;First noise sequence and noise interference bandwidth are passed into first multiplier, then the output result and carrier signal are passed into adder, and first complex signal is output by direct digital synthesizer;First complex signal and second noise sequence are passed into complex multiplier, and second complex signal is output;Second complex signal and third noise sequence are passed into second multiplier, and noise interference signal is output.The generation of multi-mode noise interference signal dynamically flexibly is realized.

This invention discloses a segmented quadrupole system incorporating phase control, comprising a segmented quadrupole structure, a direct digital synthesizer, a first phase shifting device, a second phase shifting device, a first radio frequency high voltage output device, and a second radio frequency high voltage output device. Compared to traditional quadrupole systems that increase radio frequency high voltage and frequency, this invention achieves high resolution while reducing electrical noise and power loss in the radio frequency system and improving power supply control accuracy, as it eliminates the need to increase high voltage and frequency. This results in higher instrument reliability while maintaining high resolution. By dividing the long quadrupole into multiple short segments—at least one first quadrupole and at least one second quadrupole—the manufacturing precision requirements for single-segment quadrupole electrodes are effectively reduced, simplifying the manufacturing process, improving overall mechanical stability, and minimizing the impact of thermal deformation and mechanical vibration on mass spectrometer performance.

The invention discloses a low-speed speed measurement method for a sine frequency modulation Doppler radar, and mainly solves the problems that the existing debugging test is complicated, and the speed measurement cannot be carried out due to easy lock losing during low-speed flight. The implementation scheme comprises the following steps: determining side frequency times, a modulation index and a modulation frequency; a DDS is used for digitally synthesizing a sine frequency modulation signal, the sine frequency modulation signal is mixed with a local oscillator signal generated by a PLL to generate a radio frequency sine frequency modulation signal, and the radio frequency sine frequency modulation signal is transmitted to specific four directions in turn according to a period; performing phase shifting and frequency mixing on a coupling signal of the echo signal and the transmitting signal, performing down-conversion to a base band, and performing band-pass filtering to obtain a side frequency component containing a Doppler frequency spectrum; carrying out IQ demodulation on the side frequency component and IQ two-path coherent reference signals thereof to obtain an IQ signal of a Doppler spectrum; and calculating the IQ signal of the Doppler frequency to obtain the speed information of the aerial carrier. The method greatly reduces the isolation index requirement of the receiving / transmitting antenna of the Doppler radar, improves the speed measurement capability of the Doppler radar during low-altitude low-speed flight, and can be used for airborne Doppler radars.

The invention provides an AD9361-based radio interference signal generation method, which is characterized in that a baseband interference signal is generated in an FPGA (Field Programmable Gate Array) through the function configuration of a multi-path parallel DDS (Direct Digital Synthesizer) and an upper computer, the baseband interference signal and a local oscillator signal are mixed through the configuration of AD9361, and then the interference signal is output in a radio frequency manner, and the AD9361-based radio interference signal generation method has four interference modes, the interference modes comprise a single-tone interference mode, a frequency sweeping interference mode, a frequency hopping interference mode and a suppression interference mode. According to the invention, target interference capability of multiple frequency bands and multiple communication systems can be realized, and the effect of changing flexibility into controllability is achieved; according to AD9361 configuration, effective power control can be utilized to the maximum extent, and the output management capability of the system is improved.

The invention discloses a method for upgrading and transforming an analog simulation system based on point-to-point communication, which comprises the following steps of: upgrading a communication protocol, forming communication middleware by establishing a DDS (Direct Digital Synthesizer) information warehouse and packaging a communication data interface in an original system, and establishing connection between operating console software and the DDS information warehouse through the communication middleware, completing data subscription and distribution; the method comprises the following steps: transforming data sending ends of software in an original system, only reserving a sending end generated by a data source and ignoring a forwarding data link among the software through data interface arrangement and transmission process tracing, then calling a corresponding data distribution interface function of communication middleware to replace an original sending end module, and uploading data to a communication bus; each software receiving end in an original system is transformed, each software subscribes to a data interface which needs to be received, then a corresponding data receiving interface function of communication middleware is called to replace an original TCP receiving end module, and needed data is obtained from a communication bus.

An antenna circuit for a drilling system beacon. The circuit includes a carrier direct digital synthesizer (“DDS”) and a communication DDS that generate respective signals used to drive an antenna and produce a beacon signal having both carrier and communication components. To obtain an accurate indication of carrier amplitude for feedback control, the beacon signal is synchronously mixed with the carrier DDS signal using an analog switch or similar mixer. The resulting mixed signal contains sum and difference components that are passed through a lowpass filter to remove contributions from the communication component. The filtered output provides a direct current (“DC”) value representative only of the carrier amplitude, enabling a processor to regulate drive parameters without contamination from communication signals.

A DDS circuit includes a phase accumulator circuit. The phase accumulator circuit includes a clock input being configured to receive a clock signal. The phase accumulator circuit includes a frequency tuning register configured to receive a frequency tuning word (FTW), and a phase shift register configured to receive a phase shift word (PSW). The phase accumulator circuit also includes a phase increment sub-circuit configured to increment a phase signal output by the phase accumulator circuit by a predetermined phase increment based on the clock signal and / or based on the FTW. The phase accumulator circuit further includes a feedback path configured to feed back the phase signal to the phase increment sub-circuit. The phase accumulator circuit further includes a phase correction sub-circuit configured to adapt the phase signal fed back to the phase increment sub-circuit based on the phase shift word.

The invention provides a cloud edge collaborative data distribution method and system. Relates to a digital information transmission method and system. The method comprises the following steps: acquiring a service priority of to-be-distributed data; when the service priority is a high priority, routing the data to be distributed to a DDS (Direct Digital Synthesizer) transmission channel; adjusting the QoS strategy of the DDS transmission channel based on the current network state of the edge node; and distributing the data to be distributed through a DDS transmission channel according to the adjusted QoS strategy. When the service priority is a low priority, routing the data to be distributed to an MQTT transmission channel; and transmitting the to-be-distributed data to a cloud end in a zero analysis mode.

The invention, which relates to the technical field of the precision measuring instrument, discloses a low-temperature-drift digital phase-locked eddy current sensor circuit comprising an MCU, an excitation signal generation module, an AC bridge module, and a high-speed precision ADC sampling module. The excitation signal generation module generates a high-stability 50kHz sine wave excitation signal through high-precision DAC and DMA transmission by adopting a DDS (Direct Digital Synthesizer) mode; the AC bridge module suppresses common-mode interference caused by probe temperature excursion by using a reference coil; the high-speed precise ADC sampling module is used for synchronously digitizing bridge output and excitation signals; the temperature compensation module performs real-time software compensation on the residual temperature excursion through an integrated digital temperature sensor and a pre-calibrated polynomial model; a digital phase-locked demodulation algorithm is realized in the MCU, and a displacement related amplitude is accurately extracted through digital multiplication and low-pass filtering. The circuit fundamentally inhibits temperature drift from hardware and software levels, and realizes high-precision and high-stability eddy current displacement measurement.

The invention provides a deep learning-based countering airspace signal processing method and device, and belongs to the technical field of airspace signal countering. The method comprises the following steps: acquiring an unmanned aerial vehicle control signal, carrying out online learning on the control signal by adopting a 32-bit fixed-point operation artificial neural network ANN, and analyzing to obtain an analysis result containing the frequency, the frequency point and the rate of the control signal; the artificial neural network ANN is realized through FPGA (Field Programmable Gate Array) modularization; based on the analysis result, generating a digital source signal with the same frequency as the unmanned aerial vehicle control signal; performing FSK modulation on the digital source signal by adopting a DDS (Direct Digital Synthesizer) algorithm; and carrying out power amplification and directional emission on the modulated signal to realize airspace signal countering. The complex signal analysis precision can be improved, the hardware resource consumption is reduced, and the real-time performance and the cost are both considered.

The invention relates to a DDS data dynamic subscription method and device, a record playback system, electronic equipment and a storage medium, the method is used for dynamic subscription of DDS data of different types of sending end DDSs and receiving end DDSs, and the method comprises the following steps: obtaining IDL files corresponding to the sending end DDSs; automatically generating an executable Python subscription script according to the IDL file; the method comprises the steps of receiving a Python subscription script, executing the Python subscription script, creating a DataReader according to the Python subscription script, receiving a corresponding original message through the DataReader after the Python subscription script monitors that a sending end DDS releases data, analyzing the original message, and outputting the analyzed data. According to the data subscription method and device, a DDS subscription code does not need to be manually written and the SDKs of different manufacturers do not need to be adapted, the user can complete data subscription only by uploading the IDL, and the development efficiency is greatly improved.

In one example, an RF oscillator system includes a laser source configured to emit laser light, a housing, a crystalline microresonator disposed within the housing, and a photonic integrated circuit disposed within the housing, the photonic integrated circuit including an optical waveguide network and configured to generate a clock signal based on the laser light. The RF oscillator system may further include at least one photonic wirebond configured to couple the laser light between the optical waveguide network and the crystalline microresonator via evanescent coupling; laser control circuitry disposed within the housing and configured to lock a frequency of the laser light to a resonance of the microresonator to generate the clock signal; and a direct digital synthesizer disposed within the housing and configured to produce a tunable oscillator signal based on the clock signal.

The invention provides a low-phase-noise frequency agility frequency synthesizer based on a DDS (Direct Digital Synthesizer). The frequency synthesizer comprises a frequency mixer, the frequency mixer is connected with a C wave band dot frequency source and a P wave band frequency hopping source, and the output of the frequency mixer is output after being filtered and amplified. According to the invention, through the three-stage architecture of the crystal oscillator, the comb spectrum generator and the rapid frequency conversion, the requirements of the system on core indexes of phase noise, spurious suppression, agility speed and the like are met, and a high-reliability local oscillation source can be provided for a high-frequency system; the low phase noise can be effectively ensured by suppressing harmonic distortion based on the comb spectrum generator, the phase jitter problem in frequency synthesis can be significantly reduced based on the design of the P-band frequency hopping source, and by combining the high resolution of the frequency hopping source and the broadband coverage capability of the dot frequency source, the extremely wide range output can be realized, the multi-stage PLL cascade is not needed, and the circuit complexity is significantly reduced.

A sine wave generation circuit includes: a first direct digital synthesizer generating a digital sine wave fundamental signal having a frequency f0 in a normal operation mode and a calibration mode; a second direct digital synthesizer generating a digital second harmonic correction signal having a frequency 2f0 in the normal operation mode; a correction circuit superimposing the digital second harmonic correction signal on the digital sine wave fundamental signal; a D / A converter converting an output of the correction circuit into an analog sine wave signal; an output buffer receiving the analog sine wave signal and outputting an analog sine wave output signal; an A / D converter converting the analog sine wave output signal into a digital signal in the calibration mode; and a processing circuit generating a spectrum based on the digital signal in the calibration mode and setting a parameter of the second direct digital synthesizer based on the spectrum.

The invention discloses a microwave photon fast frequency hopping signal generation system and method. The system comprises a master laser, a light beam splitter, a slave laser, a semiconductor optical amplifier, an IQ modulator and a photoelectric detector. The main laser generates a single-frequency optical signal, and the single-frequency optical signal is modulated by the low-carrier-frequency radio-frequency signal gain switch to generate a wide-spectrum optical frequency comb; the method comprises the following steps of: dividing an optical signal into an upper branch and a lower branch through an optical beam splitter, injecting the optical signal into a slave laser through a polarization controller and a circulator to perform frequency-selecting filtering, then increasing the rejection ratio through a semiconductor optical amplifier, and loading the lower branch to a communication signal to control the phase difference between an I path and a Q path in a modulator, when carrier suppression single sideband modulation is realized, a + 1 order sideband and a-1 order sideband can be flexibly selected; and finally, beat frequency is carried out on the upper and lower branches through a photoelectric detector to realize communication signal output in a double-frequency coverage range. According to the invention, the difficulty of realizing a frequency hopping signal in a high carrier frequency and broadband range by a direct digital synthesizer in an electronic domain is greatly reduced.

The invention relates to a lightweight DDS (Direct Digital Synthesizer) message sending method, which comprises the following steps that: a DDS protocol stack module receives sample data sent by an application program, and calculates the maximum total length of a WriteHistories management node and an RTPS (Real-time Transport Packet Switching) message according to the sample data; the DDS protocol stack module applies for a serialized memory according to the maximum total length; the DDS protocol stack module serializes the sample data to the Payload of the DATA sub-message of the RTPS message; the RTPS message is inserted into a Cache node of a WriterHistories (WriterHistories); and sending the complete RTPS message through the network. According to the method, the data sending process is optimized, and the memory copying frequency and the memory application frequency are reduced, so that the processing time loss of a data sending interface is reduced, and the real-time performance and efficiency of data transmission are improved.

The application discloses a nanosecond pulse laser driving control device and method, relates to the technical field of nanosecond pulse lasers, and comprises a main control module connected with a digital-analog conversion module, a direct digital synthesizer module, a reference operation and current monitoring module, a signal output selection module and a signal coupling and current monitoring module respectively; the reference operation and current monitoring module is connected with the digital-analog conversion module; a pulse signal generation and conditioning module is connected with the direct digital synthesizer module and the signal output selection module respectively; the signal coupling and current monitoring module is connected with the signal output selection module; the reference operation and current monitoring module and the signal coupling and current monitoring module are connected with a target nanosecond pulse laser, and the application can improve the stability and reliability in the driving control process of the target nanosecond pulse laser.

The invention relates to a DDS (Direct Digital Synthesizer) data playback method and system, and the method comprises the steps: obtaining DDS original data, and recording an original transmission frequency; screening the DDS original data according to a specified field to obtain a visual data set; in the slow playing scene, calculating an acquisition interval according to the set playback magnification and the original sending frequency, and calculating a target receiving frequency in the slow playing scene based on the acquisition interval; under the quick playing scene, downsampling processing is performed on the visual data set, a downsampling interval is calculated according to the playback magnification and the original sending frequency, and a target receiving frequency under the quick playing scene is calculated by using an automatic matching method based on the downsampling interval; and performing visual rendering display on the final visual data set based on the target receiving frequency. According to the invention, the limitation of existing fixed sampling can be broken through, downsampling is carried out in a fast playback scene to ensure rendering fluency, the acquisition interval is adjusted in a slow playback scene to reserve data details, and adaptive optimization at different playback speeds is realized.

The invention relates to a laser frequency and power control system for an atom magnetometer, which realizes laser frequency stability through saturated absorption, realizes laser power stability, amplitude square wave control and laser frequency control through controlling an acousto-optic modulator, inhibits laser power fluctuation and low-frequency noise interference, and improves the stability of the atom magnetometer. According to the atomic magnetometer provided by the invention, the acoustic optical modulator is used for driving and controlling the acoustic optical modulator, so that the detection precision of the atomic magnetometer is remarkably improved, the acoustic optical modulator is driven and controlled through a circuit of a direct digital synthesizer (DDS) chip and a field programmable gate array (FPGA), and the miniaturization of the atomic magnetometer is facilitated.

The invention discloses a phase external synchronization method of a radio frequency power supply in the technical field of radio frequency power supplies, which comprises the following steps: providing a synchronous clock by an external reference clock source, and distributing the synchronous clock to a master and a slave through a synchronous interface to serve as a system synchronous clock of an internal DDS (Direct Digital Synthesizer) and an ADC (Analog to Digital Converter); the slave sends out a synchronizing signal according to the received host test signal, calculates path inherent delay according to the phase difference between the test signal and the synchronizing signal and stores the path inherent delay; the slave generates an ideal reference signal, an actual radio frequency signal is sampled through an ADC, an actual baseband signal is obtained through a DDC module, a phase error is solved after a complex error is calculated, a phase correction value is output through a PID controller, and a final offset value is obtained by combining a target phase and path inherent delay and written into a DDS phase offset register in real time. According to the phase external synchronization method, through external clock source sharing, path delay automatic calibration and closed-loop phase control, the problems that a traditional simulation PLL is insufficient in static precision and poor in dynamic stability are solved, and dynamic high-precision stable synchronization is achieved.

The invention belongs to the technical field of laser driving, and relates to a laser driving system with optical waveform feedback. The system comprises a driving circuit, an optical feedback circuit and a control system, the driving circuit is a multi-phase interleaved BUCK circuit and is used for providing large-current and low-ripple driving pulse current for the laser; the optical feedback circuit comprises a photoelectric detector, a trans-impedance amplifier and a fully differential amplifier, and is used for collecting a laser signal output by the laser and converting the laser signal into an electric feedback signal; the control system comprises an FPGA, a high-speed ADC and an upper computer. The FPGA comprises a waveform processing unit, a DDS (Direct Digital Synthesizer) module, a digital integrator and a SerDes module; and the FPGA realizes laser waveform high-fidelity driving and stable output power control through double closed-loop control. According to the invention, a waveform feedback technology is adopted, high-fidelity driving of a laser output waveform is realized, and the stability of output power can still be maintained after waveform adjustment.

The invention discloses a variable-rate FSK (Frequency Shift Keying) modulation and demodulation method, device and system based on an FPGA (Field Programmable Gate Array), and belongs to the technical field of FSK modulation and demodulation. Based on the FPGA, the method comprises the following steps of: controlling selection of a frequency word according to data to be sent during signal transmission, controlling updating of the frequency word according to a preset symbol rate, controlling a DDS (Direct Digital Synthesizer) to generate FSK modulation signals with different modulation orders by the frequency word; the operation frequency of the DDS is a modulation signal sampling rate; when a signal is received, a variable multiple CIC decimation filter is firstly used for decimation according to integral multiples, the sampling rate of the received signal is reduced, then Farrow structure fractional multiple decimation filtering is used for adjusting the sampling rate to a first symbol rate, and FSK demodulation and bit synchronization recover data in the adjusted signal. According to the invention, the transmission rate can be dynamically adjusted according to the channel state, the spectrum resource utilization rate is improved, and the transmission performance is improved.