  In this work, a complementary resonant structure etched on the ground plane
of a microstrip line is proposed for characterizing dielectric materials. The
resonant sensor is designed to operate in S-band (2 to 4 GHz). The sensor is
designed in an electromagnetic simulator to generate its transmission response,
electric and magnetic field maps. A numerical model of the sensor is
established to extract the electric permittivity of dielectric samples. The
sensor is fabricated on a soft microwave laminate using a rapid
photolithography technique. The electric permittivity values of wood, Teflon,
and RT/duroid 5880LZ are determined by using the sensor. The permittivity
values are found consistent with those available in the literature.
