S Rajesh, M R Sanjay Kumar, B L Manu Datta, RRangegowda, J Parinitha
Communication and digital signal processing applications of today are often developed as fully integrated systems on one single chip and are implemented as application specific integrated circuits using e.g. VLSI technology. As the systems are getting more and more complex, in terms of speed and performance, the chip size and the design time tend to increase rapidly. This will result in search for cheaper and less time consuming alternatives. One alternative is field programmable gate arrays, so called FPGAs. The FPGAs are getting faster, cheaper and the number of gates increases all the time. The purpose of this paper was to develop a waveform generator to generate arbitrary waveforms based on DDS used for radio/radar applications. DDS technique is widely applicable and simple. Direct Digital Synthesizer (DDS) is a frequency synthesizer and it can generate arbitrary waveforms by using single, fixed frequency reference clock. Some of the DDS Applications are: function generators, modulators. The waveform generator was developed and implemented using a Virtex-6 FPGA from Xilinx and a D/A Converter from Analog Devices. The information of the signal to generate a waveform is programmed using Matlab. In Matlab, we will enter the amplitude, frequency and phase of the waveform to be generated and then load the values of Samples in FPGA RAM. The Data Samples are send to DAC using FMC port. DAC will receive that data from FPGA and then it converts to analog signal. Testing of the whole system, both hardware and software, was done. The system is able to generate sine and chirp waveforms and other arbitrary waveforms.