Discoidal vs Tubular Feed-through Capacitors

The coupling impedance and its frequency dependency of tubular and disc-type ceramic feed-through capacitors are investigated theoretically and experimentally. The superiority of discoidal feed-throughs with respect to high-frequency performance and mechanical ruggedness is shown. In the UHF range filtering gains of 20 db to 30 db can be achieved when replacing tubular feed-throughs by discoidal units. Because of this merit, improved shielding methods, which are discussed, are required.