A very wide bandwidth digital VCO using quadrature frequency multiplication and division implemented in AlGaAs/GaAs HBT's.
Pete M. CampbellHans J. GreubAtul GargA. SteidlSteven R. CarloughMatthew W. ErnestRobert F. PhilhowerCliff A. MaierRussell P. KraftJohn F. McDonaldPublished in: IEEE Trans. Very Large Scale Integr. Syst. (1998)