Microstrip patch sensor for measurement of the permittivity of homogeneousdielectric materials

An application of a small air-spaced coaxially fed rectangular microstrip p atch antenna as a sensor for permittivity measurement is presented. The mod els used for the calculation of the permittivity from the shift in the reso nant frequency for solid and liquid materials are described. The models are experimentally verified by measurements for several liquid and solid sampl es, The results are compared with those obtained using standard techniques, namely, coaxial probe and waveguide cell measurements, An error correction technique for the elimination of the systematic error of the measurement i s also included.