GaAs on Si as a substrate for microwave and millimeter-wave monolithic integration

The authors calculated the effective dielectric constant, characteristic impedance, and dielectric loss of a shielded microstrip line manufacture on namely GaAs, Si, and GaAs/Si. Dielectronic loss versus frequency for the GaAs and Si substrates are shown. The same parameters for GaAs/Si substrate were plotted for two different resistivities of the GaAs overlay material, and for each of three different GaAs overlayer thicknesses. The measurements covered the 10-100-GHz frequency range. Depending on the thickness, results show that high-resistivity GaAs epitaxial layers on Si substrates having moderate resistivities reduce the dielectric loss