πtype lowpass filter for wideband noise suppression in small size package

The design and implementation of a moral π-type lowpass filter for wideband suppression of simultaneous switching noise in a small size, mixed signal system-in-package is reported. The filter consists of a continous conductive layer, a segmented conductive layer and a thin-film insulator having high dielectric constant between the two to replace the conventional power/ground planes in a package. From 0.55 to 4 GHz, the insertion loss of testing points, with a distance of only 4 mm, is measured to be greater than -40 dB for this filter. The proposed structure is suitable for low-cost, wideband noise supression in a highly integrated mixed signal system-in-package.