Anisotropy and frequency dependence determination of relative dielectric constant for sapphire and silicon carbide substrates

Study results of frequency properties of sapphire and 4H-SiC{0001} silicon carbide substrate show availability of anisotropy and dispersion of effective dielectric constant ε(f). In both cases a value of ε(f) decreases with frequency f increasing. For a sapphire substrate the dispersion (ε(f=3.3 GHz)=9.32 and ε(f=37.6GHz)=8.62) is 7.5 percent, anisotropy is lesser than 0.5 percent. For 4H-SiC substrates a maximum value of dispersion (ε(f=3.47 GHz)=8.34 and ε(f=46.63 GHz)=7.77) is 6.8 percent, and anisotropy is 2.8 percent.