Group Delay Time Matched CMOS Microwave Frequency Doubler

PURPOSE: A ground delay time matched CMOS microwave frequency multiplier is provided to adjust a phase error between two input signals of an XOR gate by controlling a group delay time with voltage controlled delay line. CONSTITUTION: In a ground delay time matched CMOS microwave frequency multiplier, a hysteresis comparator(100) receives an input signal and converts a sinusoidal wave into a square wave. The hysteresis comparator controls a duty cycle of the square wave according to a change of a control voltage constant. A delay element(200) is installed at an output terminal of the hysteresis comparator. The delay element delays the square wave inputted through the hysteresis comparator by 90°, and a voltage controlled delay line(300) is installed in parallel with the delay element. The voltage controlled delay line compensates the group delay time of the delay signal outputted through the delay element according to the change of the control voltage. An XOR gate(400) outputs a desired amplified signal through two signals inputted from the delay element and the voltage controlled delay line.