Question

The shape of the rectangular window function is changed to other function such as Hamming and Blackman window functions so that

• A. the sidelobe amplitude decreases while decreasing transition band width
• B. the sidelobe amplitude increases while increasing transition band width
• C. the sidelobe amplitude decreases while increasing transition band width
• D. the sidelobe amplitude increases while decreasing transition band width

Hint:

Windowing is used to reduce the spectral leakage of a finite duration signal. Remember that better side lobe suppression comes at the cost of increased transition bandwidth.

Answer 1

The Correct Option is C

The purpose of changing the window function from a rectangular window to Hamming or Blackman windows is to reduce the sidelobe amplitude while increasing the transition band width. The rectangular window has the smallest transition width but the highest sidelobe amplitude, whereas other windows provide reduction in side lobes, but at the expense of increased transition widths.