200 You Know Arbitrary Waveform Generator Signal Conditioning Circuit Design

The waveform generator can generate a varity of waveforms and arbitrarywaveform drawn by ueser，which play a important role in the field of electronicmeasuring. Arbitrary waveform generator mainly consists of two parts,digital circuitthan generate initialization waveform and analog processing channel.The thesis focuses on the design and realization of200MSPS arbitrary waveformgenerator’s signal processing channel.This thesis mainly covers the following content:1. By analyzing output signal charactiristics and principles of the DDS module,thehardware circuit of the analog processing channel was executed.The device selection isdone.2. By analyzing output signal spectrum of the DDS module,the program thatElliptic low-pass filter circuit to filter spurious spectrum was confirmed.DAC outputsignal amplitude of the DDS module was analyzed. To achieve amplitude control,theprogram of combining fine and coarse control is selected.Coarse range is determinedthrough different combinations of amplification and attenuation;and amplitude finecontrol is achieved by changing DAC’s output amplitude.Meanwhile,device selection ofamplifier and attenuator is also done. The signal processing channel contain squarewave generating circuit and edge controller for rectangular pulse.Square wave is ouputby hysteresis comparator,and hysteresis comparator principle and duty cycle controlmethod is analyzed.The principle of the edge controller for rectangular pulse wasexplained,and device selection were described.3. The signal integrity problems is specifically analyzed,including reflecioncrosstalk and power collapse.The accuracy and flatness of the signal amplitude wasoptimized.4. Test process are presented according to desgin requirements.The results of thetest prove the effectiveness and practicality of the design of the analog channel.