Continuously variable gigahertz phase-shifter IC covering more than one frequency decade

A monolithic integrated silicon bipolar circuit which allows phase shifting of arbitrarily shaped clock signals by 0 to -2π within a frequency range from about 60 MHz to 1.8 GHz is described. The phase can be adjusted by a single potentiometer or by an externally applied voltage. The wide frequency and phase-shifting ranges were achieved by a mainly digital circuit principle. The temperature coefficient of the phase can be adjusted within a specific range. The circuit was realized by use of a very conservative 2-μm standard technology