A Ku-band transversal filter using directional Couplers made of a multilayer ceramic

A Ku-band transversal filter using directional couplers has been developed. Calculations confirm that the increase in insertion loss due to a decreasing Q-factor is much less than that for a resonator filter. The filter is accurately designed by using three-dimensional electro-magnetic field analysis, and is made of a multilayer ceramic to obtain high homogeneity. Measured transmission characteristics agree well with calculated values. Such a filter type is believed to be more suitable for MICs and MMICs than a resonator filter because of low insertion loss.