A Versatile Hyperbolic Cosine Window for Spectral Resolution

Abstract

A simple but versatile hyperbolic cosine window function is presented in this paper, which has two terms in the time domain. A parameter p in the window can be varied to make the mainlobe width of the window function to approach that of a rectangular window ($\pm 1/T,$) while maintaining higher sidelobe decay (12 dB/octave.) Even though such behavior has been demonstrated by the two-term polynomial window, it suffers from the limitation that only some discrete values of mainlobe widths can be achieved in the range, $\pm 1/T$ to $\pm 1.5/T$. The proposed hyperbolic cosine window has no such limitation; one can achieve any desired value of mainlobe width in the above range. The proposed window can be employed for applications involving spectral resolution.