Cavity reflection-transmission-perturbation method for foliage relative permittivity measurement

The information of foliage relative permittivity is one of important properties in the design of microwave communications or radar systems, especially in forest area. In this paper, the measurement of foliage relative permittivity is proposed based on the cavity reflection-transmission-perturbation method. The technique that uses a rectangular waveguide combines the reflection/transmission method that can keep the foliage undestroyed and the cavity perturbation method that has high accuracy. Prior to the foliage relative permittivity measurement, the proposed method is numerically analyzed based on rectangular waveguide and then experimentally verified for some known dielectric materials. From the measurement of some foliage samples in Indonesia, the relative permittivity of foliage shows the different result that depends on the moisture content in each foliage sample. It shows that the proposed method is easier and more suitable as the foliage can be kept undestroyed for the measurement.