On approximated linear-phase recursive digital filters
Kuo-Hsien Yeh, Hung‐Ching Lu, Jie-Cherng Liu · International Journal of Electronics · 1995
The recursive forms to approximate the causal linear-phase IIR digital filters are studied. Actual causal linear-phase IIR digital filters have been proposed (Clements and Pease 1989); however, the lack of rational expressions of the considered systems render them unrealizable. As a consequence, applications for this kind of filter do not exist. In this paper, based on the Pade approximation and the eigenfilter design, the approximations of linear-phase recursive representations of the filters are proposed for practical applications. Experimental results show good approximation on phase linearity. Finally, the magnitude response is designed to meet the specifications in the passband of the low-pass filter.