Waveform signal generator with optionally adjustable output signal offset

Abstract

The invention relates to a waveform signal generator with optionally adjustable output signal offset, which comprises a frequency control word, a phase accumulator, an address accumulator, a waveform lookup table, a divider, an adder, a data negator, a D / A converter, and a low pass filter. On the basis of the prior art, the storage mode of the waveform lookup table is changed according to the characteristics of a waveform signal, and the storage space is saved; the size of the output waveform signal data is changed by adjusting a dividing coefficient of the divider; and the adder is arranged between the divider and the data negator, the offset in the vertical direction of the waveform signal is adjusted by changing the adding coefficient of the adder, and the waveform signal is transmitted to the data negator, passes through the D / A converter and the low pass filter and is output finally. Due to the adoption of the waveform signal generator with the optionally adjustable output signal offset, the frequency, amplitude and offset of the output waveform signal can be flexibly adjusted so as to meet the requirement of a user on the waveform signal.

Description

technical field [0001] The present invention relates to a direct digital frequency synthesis (Direct Digital Frequency Synthesis referred to as DDS or DDFS) method, in particular to design a waveform signal generator with arbitrarily adjustable output signal offset based on FPGA (Field-Programmable Gate Array) chip. Background technique [0002] Direct digital frequency synthesizer has the advantages of low hardware requirements, fast frequency switching speed, high frequency resolution, etc., and has been widely used in automatic measurement and control systems, instrumentation, communication and other fields. Direct digital frequency synthesizer has become the leader in modern frequency synthesis technology because of its superior performance and characteristics different from other frequency synthesis methods. It is embodied in relatively wide bandwidth, short frequency conversion time, high frequency resolution, continuous output phase, wideband quadrature signal and oth...

AI Technical Summary

Problems solved by technology

However, the amplitude adjustment method can only adjust the amplitude of the waveform signal, without considering the fact that the output waveform signal will have a certain offset in the vertical direction; if the user needs a voltage waveform with 0V as the horizontal line, but adopts the current When the method performs amplitude modulation, every time the division coefficient is changed, the output waveform signal will deviate by a certain value in the vertical direction, that is, the degree of deviation from the 0V horizontal line is different, which cannot directly meet the actual needs

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