What is Antenna gain of Dielectric chip antenna used with DWM1000 modules?

Have anyone measured antenna gain of Dielectric Chip Antenna used with DWM1000 modules ?
I want to limit my transmission power under regulatory limits hence I am understanding ways to control it via software configurations.
I learned about 0x1E register which is used to set gain of internal amplifiers within DWM1000 modules, also i am unable to understand how can i correlate this gain value with transmission power in dBm ?

hi Andy
Find datasheet for the antenna attached.
How this antenna performs on the DWM1000 please see the DWM1000 datasheet available from our website.
DWM1000 Chip antenna.pdf (413.3 KB)