What is the system function for a two pole band pass filter that has the centre of its pass band at ω=π/2, zero its frequency response characteristic at ω=0 and at ω=π, and its magnitude response is 1/√2 at ω=4π/9?#

• A. 0.15(1-z^-2)/(1+0.7z^-2 )
• B. 0.15(1+z^-2)/(1-0.7z^-2 )
• C. 0.15(1-z^-2)/(1-0.7z^-2 )
• D. 0.15(1+z^-2)/(1+0.7z^-2 )