W-Band Permittivity Measurements Using a Free-Space Material Measurement Technique

In this paper, a free-space material measurement technique is discussed in W-band(75~110 GHz). For the accurate measurement of S-parameters of an MUT(Material Under Test) in free space, a W-band quasi-optical free-space material measurement system, less affected by the measurement environments, is discussed, and GRL(Gated Reflect Line) method for calibrating the measurement system is described. Proposed technique is verified for `Air` and measurement results for arystal plates of thickness 1.1 mm, 2 mm, 2.75 mm and 5 mm are also shown.