A harmonic cancellation-based high-frequency on-chip sinusoidal signal generator with calibration using a coarse-fine delay cell

An on-chip high-frequency sinusoidal signal generator with a calibration circuit based on a coarse-fine delay cell is presented in this work. The proposed signal generator is based on harmonic cancellation by adding scaled and time-shifted versions of a periodic signal. However, as we increase the target frequency of the generated signal, harmonic cancellation can be severely degraded by timing issues, degrading in turn the spectral purity of the generated signal. This paper proposes an architecture of a harmonic cancellation-based sinusoidal signal generator including a calibration circuit. The calibration circuit is based on a coarse-fine delay cell that can correct timing inaccuracies. Postlayout simulations of the proposed generator in FD-SOI 28 nm technology show a THD better than -60 dB in the frequency range from 173 MHz to 2 GHz.