The present application describes modulators of CCR3 of formula : . The method of forming a filter structure includes forming a piezoelectric resonance filter over a cavity structure. The pressure-measuring device includes distance-measuring elements designed to measure the deformation of the elastic elements of the inner receptacle. An analog switch in the modulator of the invention toggles to pick up the samples of audio and place them at the designated location of each active video line scan signal. A object density classification module may classify the density into customizable categories. Next, a reset pulse is inputted to the resetting port.