Waveform generator based on direct numerical frequency synthesizer

Abstract

The utility model discloses a DDFS (direct digital frequency synthesis) device-based curve generator, which comprises the successively connected DDFS device, the numerical model transform and synthetic unit and the wave filter, among which the DDFS device consists of the phase accumulator unit and the phase amplitude conversion unit. The phase accumulator unit includes the phase accumulator and the register. The phase amplitude conversion unit is a CORDIC operation module. The utility model has the advantages that a complex wave pattern can be generated for the use in the test field. The wave pattern is provided with a plurality of frequencies which can be controlled via the frequency control field inputted to the phase accumulator. The CORDIC module replaces the traditional ROM look-up table so as to lower the cost of the hardware. Also, the use of the reiteration and the pipeline technique in the CORDIC algorithm accelerate the generation of the wave pattern.

Description

technical field [0001] The invention relates to the testing field, in particular to a waveform generator based on a direct digital frequency synthesizer. Background technique [0002] During the signal test process, it is often necessary to use waveform signals of different frequencies. For example, when we test whether the frequency response of a low-pass filter meets the requirements, we need to input many waveforms with different frequencies to the low-pass filter, and then judge whether the low-pass filter meets the requirements according to the output response. [0003] In order to obtain waveform signals of different frequencies, direct digital frequency synthesis technology has been developed rapidly in recent years. This technology has the advantages of fast frequency conversion speed, high waveform resolution, continuous phase and flexible generation of waveforms of different frequencies, etc., and has been widely used. . The structure of the commonly used wavefor...

AI Technical Summary

Problems solved by technology

[0006] The phase-to-amplitude conversion part is the key in the waveform generator. Due to the limitation of the ROM capacity, the traditional ROM look-up method has limited performance improvement; with the improvement of circuit integration level, the real-time calculation speed is also constantly improving. The method of using ROM table lookup cannot meet the requirements for speed and precision

[0007] The traditional test method uses a waveform of a single frequency to be input to the instrument under test each time, so as to repeatedly input it multiple times to test the response characteristics of different frequency waveforms. This method is relatively inefficient. If you use multiple frequency information Testing with one waveform will provide work efficiency

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