Figure 6

Simulated PSD (Power Spectral Density) spectrums of free running STNO and MASH oscillators with different feedback methods. Linewidth and Q of the oscillators are extracted by fitting a Lorentzian function to PSD spectrums. MASH oscillators exhibit a 15X enhancement in the linewidth compared to the free running STNO, exceeding Q of 10000 with all feedback methods. PSD spectrums of MASH oscillators are intentionally shifted for a clear comparison. PSD spectrum clearly shows that there are no side peaks caused by the other resonance peaks of the HBAR.