Design and implementation of spaceborne NLFM radar signal generator

This paper presents the design and implementation results of an efficient fast Fourier transform (FFT) processor for frequency-modulated continuous wave (FMCW) radar signal processing. The proposed FFT processor is designed with a memory-based FFT architecture and supports variable lengths from 64 to 4096. Moreover, it is designed with a floating-point operator to prevent the performance degradation of fixed-point operators. FMCW radar signal processing requires windowing operations to increase the target detection rate by reducing clutter side lobes, magnitude calculation operations based on the FFT results to detect the target, and accumulation operations to improve the detection performance of the target. In addition, in some applications such as the measurement of vital signs, the phase of the FFT result has to be calculated. In general, only the FFT is implemented in the hardware, and the other FMCW radar signal processing is performed in the software. The proposed FFT processor implements not only the FFT, but also windowing, accumulation, and magnitude/phase calculations in the hardware. Therefore, compared with a processor implementing only the FFT, the proposed FFT processor uses 1.69 times the hardware resources but achieves an execution time 7.32 times shorter.

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

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.543-547.838 ◽

2014 ◽

Vol 543-547 ◽

pp. 838-841

Author(s):

Shou Qiang Kang ◽

Shan Shan Li ◽

Shi Zheng ◽

Di Wu

Keyword(s):

High Precision ◽

Design Method ◽

Synthesis Method ◽

Sine Wave ◽

Signal Generator ◽

Lookup Table ◽

Direct Digital Frequency Synthesis ◽

Wave Signal ◽

Design And Implementation ◽

Three Phase

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.

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