# The phase of signal when it passes a frequency divider?

When we used the microwave frequency divider, such like: RF Bay FBS-N-14 or analog dividers in wiki.

The input signal is $$\cos(\omega t+\phi)$$, and the output signal is $$\cos(\frac{1}{2}\omega t+\theta)$$ when it passes the divide-by-2 prescaler.

what is the phase $$\theta$$ equal to? $$\frac{\phi}{2}$$ or $$\frac{\phi}{2}+\pi$$?