Complex digital filters with asymmetrical characteristics

Proposes two frequency transformations. Both map an infinite impulse response (IIR) low-pass response into a complex single-band-pass response with asymmetrical transition width. Such a response can reduce the necessary order. One method is detailed in a complex transmission line network, and robustly implemented by a ladder wave digital filter. Though the transformed network is not `one-real´, an alternative combination of voltage-based serial sections and current-based parallel sections leads to a high modularity. Another method is established in the digital domain as a multiple performance of low-pass to low-pass and shifting transformations