Transmission Lines and Transitions for High Frequency/High Speed Integrated Circuits

The transmission line is the backbone of any RF integrated circuit which uses some sort of parallel or serial signals that are run at high speeds from a transmitter to a receiver. Proper selection of a transmission line will determine insertion loss, time delay, impedance levels, cross talk, and radiation from discontinuities. Some of the conventional transmission lines used in high-speed layouts are stripline, microstrip line and embedded microstrip line. The talk will first present characteristics of these conventional transmission lines and then list their advantages and disadvantages. Next, characteristics of several newer transmission lines for application in high-speed/high-frequency integrated circuit development will be presented. These transmission lines include inverted microstrip, suspended microstrip, recessed ground microstrip, micromachined microstrip, coplanar waveguide, suspended substrate line, suspended integrated substrate line, MEMS Coaxial line, SSPP lines and non-radiative dielectric integrated guide. Characteristics of each of these transmission lines in terms of loss, cross talk and radiation will then be described. The talk will conclude by discussing transitions between different transmission lines and practical RF circuit development of novel components using the newer transmission lines.