Looking for documents about active antennas

Hi, everyone. Right now there are some "active antenna" in the market, such as the GPS antenna with LNA built in, and with the gain more than 25 dB.

I am wondering if there is any references or information about this type of antenna. And how is the DC feeding for the antenna, since there is only SMA connector on these antenna like the passive one? And can we test these antennas by using the same passive anechoic chamber measurement by using VNA?

Any information will be appreciated, thanks.

In the test, you have to use the bias tee to feed both RF and DC signal to the active antenna.

see if this paper helps.
Abhishekabs