Low-cost implementation of automotive RADARs (RAdio Detection And Ranging) is a cornerstone in the development of intelligent transportation systems. While radars have been studied and developed exhaustively during the last century due to their military (and to a lesser extent, scientific and industrial) significance , commercialization of automotive radar sensors remains a challenge due to cost and performance limitations. Silicon-based (CMOS, SiGe and BiCMOS) technologies have become popular over the last decade, enabling revolutionary growth in consumer electronics and communication systems. Silicon fabrication technology has the potential to reduce sensor development cost to an extent that will make automotive sensor technology economically viable. This dissertation presents several experimental implementations of silicon-based millimeter-wave transceivers for short-range automotive radar applications.