Design of Low Delay Bandpass Fir Filters With Maximally Flat Characteristics in the Passband and the Transmission Zeros in the Stopband

Abstract

The large group delay of the high order FIR filters is unacceptable in some applications. Therefore, recently, how to reduce the group delay of FIR filters has been studied intensively. To reduce the ringing in the time domain and to maximize the stopband attenuation, it is useful to design FIR filters with maximally flat characteristics in the passband and transmission zeros in the stopband. We present a mathematically closed form transfer function of low delay bandpass FIR filters with maximally flat amplitude in the passband and the transmission zeros in the stopband. Because of the mathematically closed form transfer function, the designing filters are very simple. Moreover, we propose a design method of low delay bandpass FIR filters with maximally flat amplitude in the passband and equiripple in the stopband by using an iterative method of a closed form transfer function and Remez algorithm.