For distinct poles, the recursive terms in the complete partial
fraction expansion of Eq.
(9.2) can be realized as a parallel sum
of complex one-pole filter
sections, thereby producing a parallel complex resonator filter
bank. Complex resonators are efficient for processing complex input
signals, and they are especially easy to work with. Note that a
complex resonator bank is similarly obtained by implementing a
diagonalized state-space model [Eq.
(G.22)].