Dielectric constant of evaporated SiO at frequencies between 13 and 103 GHz

An integrated Josephson tunnel junction and microstrip resonator have been used to determine the dielectric constant of evaporated SiO. The method is straightforward in that it uses conventional microwave techniques to calculate the impedances for different frequencies and parasitic effects are negligible. A frequency-independent value of 5.5±0.4 was calculated for the 13- to 103-GHz range. At each resonant frequency a step appeared at the corresponding voltage in the current-voltage curve. For each resonant frequency, a dielectric constant was calculated. The constant does not change appreciably from the average value of 5.5 throughout the whole frequency range, in agreement with previous measurements