Reduction of crosstalk noise between interconnect lines in CMOS RF integrated circuits

We have numerically investigated crosstalk noise between interconnect lines in CMOS RF integrated circuits. Immersed microstrip line (IMSL) and immersed coplanar waveguide (ICPW) over Si substrate were analyzed to make clear shielding effect of grounded planes to reduce crosstalk noise between parallel interconnect lines. It was shown that the crosstalk between the interconnect lines were extensively reduced by the use of IMSLs or ICPWs, compared with simple lines. However, in layout designs using ICPWs, we need consideration about the transmission loss due to the electromagnetic coupling with the lossy Si substrate. On the other hand, for IMSL configurations, the transmission loss due to the Si substrate is small, because the ground plane shields the signal line from the electromagnetic coupling with the Si substrate.