| In the field of electronic measurement, only the device under test and the testing instruments can not build a complete measuring system, an instrument provided stimulus signal is always needed because this kind of instrument can simulate the work environment or special status of the device under test. Arbitrary waveform generator is the very kind of instrument which is able to produce reliable flexible and controllable stimulus signal input to the measured system, so nowadays many researchers pay attention to its development.Based on the prototype of "1.25GSPS dual-channel arbitrary waveform generator", this thesis focuses on the phase synchronization error of the high-frequency waveform output between two channels, analyzing the possible cause with large number of tests and finally find the key points and given the improve design.The main contents of this thesis include:1. The problems existed in the design of "1.25GSPS dual-channel arbitrary waveform generator" is analyzed. Beyond large quantities of tests the cause which makes phase synchronization error of the high-frequency waveform output between two channels is found. Make it clear that new channel synchronized design is in demand.2. A new channel structure is designed in order to solve the transmission of the synchronizing signal and the placement of new module for synchronization; A dual-channel synchronous clock circuit is added to solve the random phase between accumulator clocks of two channels when the system is powered; A external circuit is placed to ensure DACs work synchronously in two channels; A change is made in the termination of phase accumulators to establish certain order of the beginning between two channels.3. A new module based on direct digital synthesizer makes it possible to generate modulated waveform now.4. A special dual-channel synchronous driver is written which makes phase synchronous or differential signal can be generated by the dual-channel as output. |
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