Multichannel DDS signal generator with precise phase control function

Abstract

The invention discloses a multichannel DDS signal generator with precise phase control function, comprising a clock generator, a multichannel DDS signal generating unit, a control system and an embedded phase correction module. Under the action of a sampling clock signal, the wave form signals output by DDS signal generating units of all channels form wave form signals with certain phase difference which is required by a user; the embedded phase correction module measures the phase difference of the output wave form signals between the channels, the actual value of the phase difference of the output wave forms between channels is obtained and fed back to the control system, the control system calculates coherent phase difference error between channels according to the actual value of the phase difference of the output wave form signals between channels and ideal value of the phase difference set by the user, phase control words output by the control system to the DDS signal generating units of all channels are regulated, the coherent phase difference error is compensated, and the phase difference error of the output wave form signals of all channels is reduced, thus the phase difference of the output wave form signals of all channels can be controlled precisely.

Description

technical field [0001] The invention relates to a DDS-based multi-channel signal generator, in particular to a multi-channel DDS signal generator with precise phase control function. Background technique [0002] DDS (Direct Digital Synthesis) signal generator is the mainstream product of the current signal generator, which has low cost, low power consumption, high resolution, fast conversion time, can generate arbitrary waveforms, and the output waveform phase is continuous when switching, etc. features. [0003] The basic principle of the DDS signal generator is based on sampling technology and computing technology, through digital synthesis to generate a signal whose frequency and phase are adjustable to a fixed reference frequency. Taking the two-channel DDS signal source as an example, its structure is as follows figure 1 As shown, it mainly includes clock generator 1, channel 1 phase accumulator 201 and channel 2 phase accumulator 301, channel 1 phase adder 202 and c...

AI Technical Summary

Problems solved by technology

Due to the difference in circuit layout and delay time between different chips, the deviation of sampling clock between channels and the delay between output channels are often caused, which is reflected in the output signal, and the phase error between the actual phase and the ideal phase is relatively large.

Therefore, for occasions requiring high phase accuracy, it is very difficult to guarantee it only physically

Images