Broadband signal generation device and method based on adaptive correction

Abstract

The invention discloses a broadband signal generation device and method based on adaptive correction. The device comprises a phase accumulation unit module, a phase amplitude conversion unit module, aDAC circuit module, a radio frequency processing circuit module, an ADC circuit module, a signal detection and processing unit module, a spurious control unit module and a spurious correction signalgeneration unit module. The method comprises the following steps: performing feedback at a DDS signal output end to perform high-speed sampling, adaptively realizing stray extraction and feature analysis of broadband output signals, obtaining frequency, amplitude and phase information of stray signals, additionally outputting N paths of correction signals or driving a parallel DAC to output N paths of correction signals in a signal generation structure, generating same-frequency, anti-phase and basically equal-amplitude correction signals, and realizing spurious suppression through synthesis of the output signals and the correction signals, wherein N > = 1. The spurious suppression effect is achieved, and the false-free dynamic range of broadband DDS output signals is widened.

Description

technical field [0001] The present invention relates to the field of direct digital synthesizers, and more specifically, to a wideband signal generation device and method based on adaptive correction. Background technique [0002] Direct Digital Synthesizer (DDS, Direct Digital Synthesizer) is widely used in radar, electronic warfare, communication, surveying and mapping, instruments and other fields, and is usually used as a signal source or excitation device to drive the work of the entire system. From the perspective of phase, the direct digital synthesizer uses the phase accumulator to accumulate the frequency control word to obtain the address information corresponding to the phase value, and maps the amplitude value of the sine and cosine function through the address of the phase value to obtain the digital sequence of the required waveform. Then the analog waveform is obtained through the DAC output. [0003] The direct digital synthesizer has the advantages of high ...

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Problems solved by technology

In order to weaken the spurs caused by phase truncation, the method of increasing phase dither and amplitude dither is adopted to disperse the energy of phase error in the whole spectrum range through random jitter, avoiding the formation of high spur peaks, and at the same time, there will be no background noise Too much change, so as to improve the spurious suppression performance. This type of method is mainly effective in truncation of periodic signals, but the spurious suppression performance of various mechanisms in the wideband bandwidth range is not good.

An ideal DAC has linear characteristics, and can convert the input frequency control word into a radio frequency output with a fixed ratio factor. Due to the influence of DAC device design performance, power supply, clock leakage and other factors, the actual DAC has nonlinear characteristics and instantaneous glitches. Such spurs mainly use balanced DAC or correction methods for some predictable signals (such as harmonics) at home and abroad. The control of frequency, phase and amplitude of this type of method is more dependent on predictability and stability. The correction method is time-consuming and laborious, and suppresses spurs. Limited scatter, not suitable for broadband applications

In addition, some researchers have achieved relatively good results by selecting a linear power supply with smaller power supply ripple and a better quality reference clock signal, optimizing the filter and electromagnetic compatibility design, and reasonably selecting the output frequency band. , but the design output effect for any broadband frequency point is still not good

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