 Posted: Mon 11:07, 04 Apr 2011 Post subject: Chirp signal based on DDS technology generation sy |
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| Chirp signal based on DDS technology generation system
Delay time. The frequency of the signal from the current plant can be set phase difference between the two signals △ a mTof × 360. . (2) signal analysis system ,MBT schuhe preise, known in determining the environment, the difference only with the current scan frequency. In this, the difference between the different frequency values at the incremental PID algorithm implemented △ ( bogey ) First [2.45e (k) A 3.5e ( Chi a 1) +1.25 e ( Chi -2 ) ], ( 3 ) where k is coefficient. 24 of Foshan University ( Natural Science) Volume 22, sine wave signal generator 3.2 Program Design program flow shown in Figure 5 . First, reset the AD7008 , the register is zero; and then load the selected sine wave frequency, phase , amplitude ; determine the scanning center amplitude , decoupling limit and the scanning frequency ( up- , down-conversion ); initial frequency of the input parameters F, termination of the frequency F,, period T; to determine the number of Ⅳ and frequency conversion value af, scanning begins. Through appropriate regulation, by the former three -band difference between the value generated by the frequency to determine the value of time required under the PID control increment correction , and thus achieve better control effect , resulting in the desired different frequency , phase And the amplitude of the sine wave. 4 Results and Analysis of chirp signal source system design , using the flowchart in Figure 5 signal of the DDS technology, advanced electronic control system can achieve linear scanning , frequency scanning , coding, scanning and other technologies help to improve wavelet The frequency, high-resolution seismic exploration to create better conditions. Phase of the automatic control system accuracy ± 6. , The frequency accuracy of 0.1Hz, amplitude control precision of 0.01mm. The practical application , the amplitude stability of the sine wave is good enough , high resolution and accuracy to meet the imaging requirements. |
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