External antenna for X-NUCLEO-GNSS1A1 or X-NUCLEO-GNSS2A1

[aziubin]

Hello!
Is external antenna included with X-NUCLEO-GNSS1A1 board (or X-NUCLEO-GNSS2A1) or it should be purchased separately? GNSS expansion board based on Teseo-LIV3F module for STM32 Nucleo Data brief does not mention external antenna, but Getting started with the X-CUBE-GNSS1 global navigation satellite system software expansion for STM32Cube does mention it: "The GPS/GLONASS/Beidou antenna included with the X-NUCLEO-GNSS1A1 or X-NUCLEO-GNSS2A1 expansion board must be connected to the antenna connector on the expansion board. "

Another related question is should this external antenna be passive or active or both variants are suitable?

Thanks.

[GalaxyQuest · Accepted solution]

Hi,

The X-NUCLEO-GNSS1A1 boards come with an antenna. This is an active antenna and you can connect this antenna to the board.

If you need to plug in a passive antenna, the power supply to the antenna needs to be removed. For this, you can depopulate R20 to remove the power supply to the antenna.

[Tesla DeLorean]

Generally anything with a connector and cable needs to be active. ie have an LNA next to the antenna element to compensate for the additional losses you're introducing.

Passives, typically you want to design on-board, with perhaps only a few inches of trace.

GNSS signals are very weak at the surface of the planet, the expectation is that antenna are outside, with a clear view of the sky. Amplifier gain can't fix poor antenna placement/situation, but affords you cable length to get it situated properly.