ISRO's programmable digital waveform generator

One of the major and common requirements for all active microware sensors is generation of the transmit modulation signal-like chirp/LFM signal, MSK, etc., which can be generated by analog or digital means. With the increasing demands of side bandwidth, longer duration chirp signals in radar systems, digital signal generation, and processing has emerged as a preferred alternative. Design and development of programmable and generic digital waveform generator (DWG) system based on Xilinx Virtex XCV600 FPGA and high-speed DAC is carried out at the Space Applications Center. ISRO is to generate required transmit chirp signal of high time-bandwidth product (~ 1000) for ISO's microwave radar sensor missions. This gives a detailed description of the design requirements, implementation details, salient performance features, and test results of this programmable and generic digital waveform generator (DWG).