Abstract: The four ports transmission formula of microwave network is used to analyze the effect of polarization, dielectric constant and loss angle tangent on the transmission efficiency in the paper, also discuss the transmission efficiency of Quartz/CE compared with the measured results. The results show that when the Quartz/CE plate with thickness 1.8mm of 1.2~18GHz band and azimuth of -40°~40°, the transmission efficiency is greater than 60%, the plate presents favorable broadband feature.