Design of sweep frequency signal source in residual stress detection platform based on Zynq

The signal generator based on DDS technology has high frequency and resolution, and is widely used in many fields such as instrument technology, radar, satellite timing, remote control and telemetry, and is one of the important directions of current signal generator research. In order to achieve a cost-effective, high frequency resolution signal source to stimulate the sensors in the residual stress detection system, this paper selects the Zynq-7020 on-chip system to control the 14-bit direct digital frequency synthesis chip AD9954 to obtain a 40Hz~1MHz sinusoidal signal output. Finally, the performance and technical parameters of the system are tested experimentally. The output signal of the signal source is stable, the signal-to-noise ratio is high, and the frequency error is within 0.1%.

Impedance Cytometry for Detection of Particle and Counting using Low Phase Noise DDFS – LUT

The biotechnology is widely growing with many technologies, still we see a large gap in real-time implementation of complete blood counting. To increase the resolution and accuracy of the measurements advanced communication DDFS can be used. The elements in Direct Digital Frequency Synthesizers (DDFS) involved are: phase accumulator, a phase to amplitude converter which also called look up table (LUT), a digital to analog converter along with active filter. Direct digital frequency synthesis is a method for generating complex high - frequency waveforms for specific applications. This DDFS generates frequency resolution which makes it ideal components use in radar system, software defined radio, modern wireless communicating system, advanced satellite navigation purpose. Use cases for high frequency we get interrupt with spurious noise, larger ROM size, and high power consumption of DDFS signal. In this paper we are proposing the use of signal generated from DDFS to impedance cytometry in which the number of particles gets detected by getting the output frequency different from the input frequency. Due to use of small frequency range of signal spurious noise, power consumption and ROM size will be less with effective performance

Analysis of Phase Truncation Error Based on Multi-Path Pseudo-Interleaved Direct Digital Frequency Synthesis

Low output frequency and spurs are main imperfections in direct digital frequency synthesis (DDFS). For increasing output frequency determined by sampling rate, the structure of multi-path pseudo-interleaved DDFS is proposed. However, it introduces more complex phase truncation error than single path DDFS. In order to analyze the effect of phase truncation error, the model of pseudo-interleaved DDFS with phase truncation is established. Based on the model, the distribution and amplitude of spur caused by phase truncation are discussed and calculated. Then some important conclusions are drawn and proved by experiment, which can provide theoretical supports for spurious performance evaluation and parameter selection while designing signal source or clock generator based on pseudo-interleaved DDFS.

Design of Dual High Precision High Resolution Frequency Synthesizer Based on AD9854

To obtain dual high-precision and high-resolution numerical control signal source, and accurately adjust the signal frequency, the paper proposed a method based on AD9854 direct digital frequency synthesis technology, design and implementation the dual high-precision and high-resolution frequency synthesizer. FPGA controlled AD9854 registers to achieve frequency modulation, and after amplification processing output by THS3001, increasing the output signal drive capability. Comprehensive consideration the anti-jamming measures, the system is stable and reliable, the output signal frequency range from 500Hz to 30MHz relative error is less than 10ppm, and can numerical adjust the sine and square wave frequency and has a sweep output mode. Compared with previous equipment, it reduces the system power consumption and volume.

Investigation of Phase-Shifting and Frequency Conversion Sinusoidal Signal Generator Based on DDS and FPGA

The direct digital frequency synthesis (DDS) technology has high frequency resolution, fast frequency switching, low phase noise and higher frequency stability, so it is widely used in communications, aerospace, instrumentation and other fields. In this paper, the DDS system was designed based on Field Programmable Gate Array (FPGA) and hardware design language (VHDL). The experimental and simulation results show that the system has stable output frequency, high frequency accuracy, adjustable frequency and phase.

The Design and Implementation of High Precision Three-Phase Sine-Wave Signal Generator

A design and implementation method of high precision three-phase sine-wave signal generator is proposed based on MCU and FPGA. For the traditional design method, direct analog synthesis method and phase locked loop (PLL) technology are used to design the signal generator. So the function, the precision and other aspects are inadequate. Aiming to the problem, a signal generator is designed based on direct digital frequency synthesis (DDS) technology. The MCU is used to control the peripheral devices and the frequency and phase control word can be obtained. The DDS module is achieved by EP4CE6E22C8 and the waveform lookup table addresses are outputted. The digital three-phase sine-wave data can be read from the lookup table. Through the three-way D/A converter and the amplifier circuit, the digital signal is converted to analog signal and the three-phase sinusoidal wave is outputted. The precision can be improved by increasing the sampling points, phase accumulator bits and D/A bits, and then, high precision three-phase sine-signal can be obtained and the adjustable frequency precision is 0.001.