Electromagnetic interference and start-up dynamics in high frequency crystal oscillator circuits

An oscillator circuit is commonly a significant source of radiated emission in electronic systems. Crystal oscillators, which have been widely used as a reference frequency standards, are susceptive to electromagnetic interference (EMI), drive-level, and start-up dynamics. The effect of radiated EMI can be both deterministic and random in nature, which shows up as jitter in the time domain and translates into the phase noise in the frequency domain. If the impact of EMI is too large, the performance of the entire system would be affected in terms of accuracy, stability, start-up, and phase noise. Experimental results and CAD simulated data provide insights into EMI and start-up dynamics and validated with the design example of 100 MHz crystal oscillator.