Complex Permittivity of GaAs and CdTe at Microwave Frequencies

The microwave dielectric constant and loss tangent of Cr-doped semi-insulatiug GaAs have been measured in the frequency range 2.5-36.0 GHz and the temperature range 300-400 K. The room temperature dielectric constant is 12.95 and the temperature coefficient alpha ( ≡ epsilon(0)^-1 d epsilon/dT) is 1.6 x 10^-4 /K. The dielectric constant and loss tangent of CdTe have been measured as functions of temperature at 15.95 GHz. The room temperature dielectric constant is 10.39 ± 0.04 and the temperature coefficient alpha is 2.5 x 10^-4 /K.