Direct digital synthesis device of pulse signal and its method

Abstract

This invention relates to a direct digital synthesizing device for pulse signals and its method including a phase synthesizer for synthesizing phase digital sequence of pulses, a waveform storage fortransforming the phase digital sequence to amplitude digital sequence of pulses, an adaptive parabola interpolation filter for interpolating and compensating the amplitude sequence to reduce the transformation error of the phase-amplitude and generate new pulse amplitude digital sequence, a DA converter converting the amplitude digital sequence to analog signals, an anti-mixed lamination low-passfilter for filtering the HF interference and re-setting up analog pulse signals.

Description

technical field [0001] The invention relates to the technical field of direct digital synthesis, in particular to a direct digital synthesis device and method for pulse signals. Background technique [0002] Direct digital synthesis (DDS) technology is currently the mainstream technology for analog function signal synthesis. Function signal generators / arbitrary waveform generators using DDS technology have the advantages of low signal distortion, high frequency adjustment resolution, and the ability to simulate arbitrary waveform functions. DDS The function signal generator / arbitrary waveform generator generally includes: a phase accumulator, a waveform data memory, a DA converter and an anti-aliasing low-pass filter, wherein the phase accumulator generates a phase sequence of the waveform by incrementally accumulating the input phase , the phase sequence changes linearly within a synthesis cycle; the waveform data memory converts the phase sequence generated by the phase ac...

AI Technical Summary

Problems solved by technology

In the prior art, the main disadvantages of DDS function signal generators / arbitrary waveform generators are: in order to reduce the phase truncation spurious interference, they need to configure a large waveform data memory, thus increasing the cost; when synthesizing pulse signals, due to The phase synthesized by the phase accumulator changes linearly with time, and the ratio of the rise time, high level time, fall time and low level time of the synthesized pulse waveform is determined by the phase-amplitude comparison table in the waveform data memory. The above parameters It cannot be adjusted independently by phase increment. To change one of the parameters individually, the waveform data table must be changed. Due to the limitation of the waveform data memory capacity, the resolution of parameter adjustment is very limited, and the operation data volume is so large that it is difficult to realize

The use of analog technology to synthesize variable-edge pulse waveforms is to limit the jump time of a square wave signal through analog signal processing to achieve the purpose of changing the rise time and fall time of the pulse, but this method cannot synthesize arbitrary rise function and fall function pulses. Waveform, the synthesis process is susceptible to interference, and the synthesis accuracy, rise time and fall time range and adjustment resolution are low

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