Abstract: A circuit is disclosed that compensates for the non-linearity of a current mode real pole producing circuit used to generate poles and zeros in complex filter circuits. The non-linearity of the prior art is compensated by driving one end of the primary pole producing capacitor with a signal derived from the drain current and fed back so as to counteract the non-linearity factors.

Abstract: A circuit is disclosed that compensates for the non-linearity of a current mode real pole producing circuit used to generate poles and zeros in complex filter circuits. The non-linearity of the prior art is compensated by driving one end of the primary pole producing capacitor with a signal derived from the drain current and fed back so as to counteract the non-linearity factors.

Abstract: Apparatus for identifying a particulate substance in suspension based on the radiation scattering behavior of the substance, which apparatus includes a source of a collimated beam of substantially monochromatic radiation which is linearly polarized along a first polarization axis, at least two modulators disposed in the path of the polarized beam for effecting polarization modulation of the polarized beam about respective dynamic axes at respective modulation frequencies, a sample of the substance being held in the path of the beam between the modulators so that radiation is scattered by the substance in a scattering plane, a polarizing device disposed in the scattering plane for passing that portion of the scattered radiation which is parallel to a second polarization axis, and a signal processing device for producing an indication of the intensity of the radiation emerging from the polarizing device at frequencies corresponding to selected elements of a Mueller matrix which characterizes the scattering prop