Discussions on measurement accuracy of complex relative permittivity using a balanced-type circular disk resonator method

A balanced-type circular disk resonator method is used to measure complex relative permittivity in the normal direction of dielectric substrates. In this paper, at first, a technique is proposed to take copper disk thickness into account to realize more accurate measurement. Secondly, a cyclo-olefin polymer (COP) substrate is measured by using four circular copper disks with different diameters to verify reasonability of the proposed technique. Finally, influence of the air-gap between substrates is discussed.