Design and Temperature Dependent Analysis of GaAs Multilayer Transmission Lines

In multilayer technology, the generated heat can not be dissipated effectively due to its multilayer structure. In this paper we designed, fabricated and characterised a group of GaAs multilayer coplanar waveguide (CPW) transmission lines and studied the effects of temperature on these components. Furthermore a de-embedding technique has been applied and the effect of de-embedding shown to be critical in removing the pads parasitics. The temperature dependents of the transmission lines are carefully analyzed from -25degC to 125degC and the results indicated that the characteristic impedances and effective dielectric constants of the transmission lines remained constant within the temperature range. These results are reported for the first time and provide an insight into the design optimization of multilayer circuits for compact 3D MMIC applications.