Design of Low Frequency Band Pass Filters for SAR applications

Technologies have advanced rapidly in the field of digital signal processing due to advances made in high speed, low cost digital integrated chips. These technologies have further stimulated ever increasing use of signal representation in digital form for purposes of transmission, measurement, control and storage. Design of digital filters especially adaptive or semi adaptive is the necessity of the hour for SAR applications. The aim of this research work is to design and evaluate the performance of 380-400 KHz Bartlett, Blackman and Chebyshev digital semi adaptive filters. XILINX and MATLAB software are used for designing of these filters. As part of practical research work these designs were translated using FPGA hardware SPARTAN-3E kit. Blackman and Chebyshev filters designed using software and hardware were tested by a sinusoidal test signal of 381 KHz along with noise and the filtered output signals are presented. These designs were optimized, analyzed, compared and evaluated keeping the sampling frequency at 5 MHz for 64 orders.