The Design And Implementation Of Portable High Precision Signal Source

With the rapid development of electronic industry in today’s society, the role of the basic electronic equipment such as signal source is becoming more and more important, but most of the existing signal source is expensive and bulky. Besides, the portable source precision is not enough. Of course they has huge limitations. Therefore, to design a portable, low cost and high accuracy arbitrary waveform generator is one of the important topics of research.Based on the arbitrary waveform generator existing research status, this thesis designed and implemented a kind of high precision, low cost, and portable arbitrary waveform generator. Since most of the modulation signal phase jump is instantaneous changes and the instantaneous change in the phase spectrum spread, according to the basic principle of spectrum analysis, baseband signal in frequency domain caused on the time domain must produce distortion on the extension, As well as between different code crosstalk problems each other. In order to reduce intersymbol interference and increase the utilization rate of frequency band, in this paper, by using the cosine roll-offs filter, square root litres cosine roll-offs filter and gaussian filter, the change of the transmission signal waveform, band-limited effectively, reduce the effects of timing error. This design first put waveform data points to the underlying storage of MCU, the waveform data through the MCU I/O port sent to the D/A module, for the modulation signal, the design adopts the block algorithm and based on look-up table, MCU receives the data through the corresponding filter will send later, by transforming the simulation was carried out on the output waveform after filtering, amplifying achieve the targets set by the corresponding processing parameters.Finally, this paper designed and implemented the arbitrary waveform generator system performance and function test, the test results show that the arbitrary waveform generator system conform to the requirements of the design, produce all sorts of waveform parameter error control within the scope of the corresponding indicators, including the underlying hardware size is 7.2 cm * 6.3 cm, through USB cable and download line don’t need other external devices and will be able to produce the required waveform, achieving the goal of the portable.