A compact plastic package with high RF isolation by subsidiary inner ground leads

A novel method to obtain a compact plastic package with higher isolation by providing subsidiary inner ground leads between outer leads is proposed an d demonstrated. The effect of the subsidiary ground leads is investigated b y using a S-dimensional electromagnetic field simulation and measuring the fabricated packages. Newly designed package with subsidiary ground leads ac hieves higher isolation by more than 10 dB at 3 GHz as compared to a conven tional package. This package is applied to GaAs SPDT switch IC's. Isolation of the switch IC's is improved by 5 dB at 3 GHz by the subsidiary inner gr ound leads. The isolation characteristics are discussed based on the equiva lent circuit extracted from the simulation results.