  An apporach for the sensing of small amounts of chemical and biochemical
material is presented. A frequency selective surface (FSS) made from asymmetric
split ring resonators (aDSR) is excited with free space radiation. Due to
interference effects a resonance occurs with a steep flank in the frequency
response which is shifted upon dielectric loading. Utilizing a strong E-field
concentration by selective loading the detection of very small amounts of probe
material becomes possible. The functionality is proven by numerical simulation
and the optimization of structure and loading is performed.
