Hi, anyone design a frequency divider? Initial condition?

Dear all,

I am designing a divide by 2 frequency divider (ILFD), still in the schematic level. It locks from 162 to 165 GHz (input), 81 to 82.5GHz (output).

For transient simulation, I set the intial condition. For example, the input is 164GHz, If I don't set inital condition, the output is still 164GHz, not divided by 2. After I set the intial condition, the output is 82GHz.

But it seems odd, since the circuit is driven, why I still need to set the intial condition?

P.S. The intial condition is for the cross-coupled lines, set the voltage to 0.

I am using SpectreRF. I know it is not accurate for this frequency, but just the first step.

Actually, any kind of frequency divider has this issue to me, so welcome for discussing:)

Thanks a lot in advance!