OPTIMAL GAIN OVERDESIGN IN ANALOG FILTERS

This paper presents a method for the overdesign of gain-shaping filter s in an optimal way. The passband minima and the stopband maxima of a filter approximation are adjusted using an iterative method, with the objective of obtaining a circuit that satisfies exactly the specificat ions when the statistical deviation in the filter transfer function du e to errors on its components is considered. The result is a filter th at can be significantly more selective than what is obtained by a simp ler overdesign method that results in an equal-ripple ideal design. Tw o different approaches are examined, one based in the development of a special approximation followed by synthesis, and the other by direct optimization of an initial classical design.