A dielectric structure applied to building components for increasing a transmittance of an RF signal is provided. The dielectric structure includes a structural body and a fixing component. The structural body includes at least one dielectric material layer, and a dielectric constant of each dielectric material layer is between 1 and 10,000. The fixing component joins the structural body and a joining component. A composite structure after the dielectric structure and building components are joined may have the RF signal of the working frequency f0 pass and reduce the reflection loss. The minimum equivalent diameter of a projection plane on a surface of the joining component of the dielectric structure on a surface through which an RF signal passes is no less than one-eighth of a working wavelength λ0 corresponding to the working frequency f0.