Error Assessment in Near-Field Free-Wave Measurements

A generalized solution for transmission and reflection coefficients of a slab in the near-field region is introduced. The use of the angular spectrum model in measuring the properties of materials is discussed, and the impact of the near-field measurement in compact free-wave systems is demonstrated. The use of a dielectric lens to reduce the diffraction of the wave from the edges of the sample, and its impact on the material properties are discussed.