Analog Channels Of High-speed Vxi Arbitrary Waveform Generator Design

Associated with the military project "high speed Arbitrary Waveform Generator (AWG) module" , this thesis focuses on the designing methodology of analog channel of the AWG developed by UESTC .Signal filtering ,amplitude and offset controlling ,square wave and modulating wave's generating are studied in detail and corresponding circuit implementation are developed. Problem relating to design of high speed board and Electro-Magnetic Compatibility (EMC) in this module is analyzed also. Hardware performance and the ability of anti-Interference are improved effectively to satisfy with the requirements of AWG. This thesis includes following four subjects: 1. According to the output spectra of Direct Digital Synthesis (DDS)system ,single low-pass filter rather than filter bank is introduced to finish filtering operation of full frequency signal, this approach leads to simpler hardware structure compared to realization by filter bank. Designing method of low-pass filter is given also in this thesis. 2. One voltage controlling manner is presented. This manner combines amplification and attenuation, and fine control and coarse control can be operated separately, it can adjust the amplitude by 1mV step in the range of 50mV to 10Vpp conveniently. 3. Principle on generating square wave by comparator is researched . A special circuit is designed to generate square wave with frequency up to 100MHZ based on a high speed hysteretic and differential comparator.4. The generation of modulation wave by wide band multiplier is designed after deep discussion on theory of the modulation wave generation. The modulation degree is adjustable.At present, ES14V21 has passed the finalized product inspection. It proves that the design in this thesis is feasible and practicable.