Influence of back ground plane on new radio frequency monochip systems

Every high frequency circuits need inductors for proper work. This is more and more true with new radio-frequency MOS transistors systems. But with the increase in frequency, lower inductors are required and MOS transistors offer less gain. Radio-frequency circuits in MOS technology are also obedient to the layout of low inductance high quality factor inductors. It has been shown that they can be better realized by microstrips. However, classical MOS digital technologies have no back ground plane under the substrate. This article analyzes the influence of parasitic back ground planes in the case of an often used coplanar solution: coplanar waveguide.