Intermittent polyphase SC structures for FIR rational interpolation

Rational sampling rate conversion factors L/M are usually obtained by cascading an L-fold upconverter followed by an M-fold downconverter. Because the traditional SC circuits employed in such cases give rise to undesired distortion effects due to the intermediary sampled-and-held signals, this paper proposes alternative solutions based on impulse sampled Intermittent Polyphase SC Structures that operate with either sampled-and-held or arbitrary input signal formats. Two alternative architectures are studied and their comparative advantages will be discussed from the viewpoints of component count and speed of the amplifiers. Behavioural level simulations illustrate well their discrete-time operation and the resulting input-output frequency responses.