Special Session: A high-frequency sinusoidal signal generation using harmonic cancellation

Abstract

An on-chip high-frequency sinusoidal signal gener-ator with a calibration circuit based on a coarse-fine delay cell is presented in this work. The harmonic cancellation principle is used for signal generation by adding scaled and time-shifted versions of a periodic signal. However, as the output frequency increases in the GHz range, the harmonic cancellation can be severely affected by non-idealities such as mismatch and variations on timing parameters (phase difference, duty cycle) of the time-shifted signals. This degrades the spectral purity of the output signal. To counter this, a calibration circuit based on a coarse-fine delay cell is integrated into the system to correct the timing parameters of the signal. Simulation results show a THD better than -60 dB in the frequency range from 500 MHz to 2GHz.