Dbx
US application 3681618, BLACKMER, DAVID E., "RMS CIRCUITS WITH BIPOLAR LOGARITHMIC CONVERTER", published 1972-08-01
US application 3714462, BLACKMER, D, "MULTIPLIER CIRCUITS", published 1973-01-30
US application 3789143, BLACKMER, D, "COMPANDER WITH CONTROL SIGNAL LOGARITHMICALLY RELATED TO THE INSTANTANEOUS RMS VALUE OF THE INPUT SIGNAL", published 1974-01-29