Self-Compensation of Alignment Tolerances for Series Capacitors in LTCC Filters with Stepped Impedance Resonators

Inhalt:
In this paper a new self-compensation technique for series capacitors in LTCC (low temperature co-fired ceramic) filters is presented. The series capacitor is required for controlling coupling and transmission zero of the SIR (stepped impedance resonators) filter setup. The capacitor is realized by electrodes placed on two layers of the laminated multi-layer setup. Due to manufacturing tolerances in the layer alignment process, deviations are caused in the desired value of the series capacitor, which might deteriorate the filter performance. By proper shaping of the series capacitor electrodes in the connection region between the SIR, a selfcompensation of these alignment tolerances can be achieved.