Specification of gain variation in Tx path

Hi,

Thanks in advance.

I designed Tx path.

Tx path doesn't have VGA.

In corner simulation, this tx path's gain changes about +/- 2dB.

I can't find the spec of gain varation in Tx path.

How can I find the spec of gain variation?

usually, what's the spec of gain variation in Tx path?

Thanks.

Depends by your system and depends by the propagation environment including multipath propagation.

I assume that you are talking about gain variations inside the transmitter, not for radio link path. In this case you have spec for upper and lower levels for TX power. Upper usually limited by FCC (or your country agency), sometimes by other conditions like coexistence and so on. Lower level can be determined by link path loss and receiver sensitivity. If your link is line-of-sight you can use Friis formula. For other links calculations more complicated and may involve channel modeling or other tools. 2dB variation looks reasonable for broadband device or for TX without power control loop.