New substrate-crosstalk reduction structure using SOI substrate [for one-chip transceiver IC]

Recently, much attention has been paid to the one-chip transceiver since it can reduce the volume and weight of mobile communication equipment. A typical one-chip transceiver IC contains RF (radio frequency), IF (intermediate frequency) and baseband circuits. and many of those consist of analog, and digital circuits. For such mixed-signal IC, the coupling through the substrate is a very important factor to limit its performance. The use of SOI technology is a promising candidate to reduce the substrate-crosstalk because it allows us to manipulate substrate resistivity. In previous papers, the effect of the substrate resistivity was mainly discussed. In this paper. we propose the new isolation structure to reduce the substrate-crosstalk using the SOI technology.