# How does one get ticks of a clock from an atomic clock's microwave signal?

I understand that in an atomic clock there is a microwave signal that is locked to the frequency of the atomic rotation. However, if one wants to extract time ticks from the microwave signal:

$$v(t) = V_0 [1+\alpha (t)] cos[2 \pi v_0 t + \phi (t)]$$ (shown below)1,

it would seem that we need to assign a tick of our clock as either when the signal crosses some threshold or when the signal reaches a peak ($$\frac{dv}{dt} = 0$$). However, in choosing one of these, your ticks will be susceptible to amplitude or phase fluctuations respectively. So, what is the standard that is used in atomic clocks, and why (i.e. maybe amplitude fluctuations are smaller than phase fluctuations or vice-versa)?

1 Enrico's Chart of Phase Noise and Two-Sample Variances by Enrico Rubiola (http://rubiola.org/pdf-static/Enrico's-chart-EFTS.pdf)

• This thing is called jitter. Your question is best answered in the electric engineer stackexchange site. Apr 3, 2020 at 23:09
• This is what phase locked loops are for. Apr 3, 2020 at 23:53