Precise measurements of dissipation factor in microwave printed circuit boards

A precise method for separating the dissipation factors associated with conductor losses and dielectric losses of printed circuit boards through a wide range of microwave frequencies is presented. This method accomplishes separation by utilizing the difference in dependence of the two losses on the dimensions of triplate-line resonators composed of printed circuit boards. To efficiently separate these two losses, a parameter which is a function of only the dimensions of the triplate-line resonator is used. Effective conductivity and the anisotropy of the conductivity in the industrial copper foil utilized for cladding is measured against surface roughness by using this method. At 10 GHz the measured effective conductivities of electrodeposited copper foil and oxygen-free rolled copper foil are about one-third and one-half that of DC conductivity, respectively. Experimentally, the anisotropic characteristics of oxygen-free rolled copper foil was clearly demonstrated. >