# How to measure the power of antenna (RF)

#### thanhvu94

Oct 1, 2016
3
Hello,

I'm doing a project about aquatic drone and we have 2 antennas on it. We want to measure the power of the two antennas and compare with each other to find out whose signal is stronger. Can you give me some ideas about this? (circuit, website, books...)

Thank you so much

#### Arouse1973

Dec 18, 2013
5,178
How do you think we can answer that with so little info. Give us all the details of your project.

#### davenn

Moderator
Sep 5, 2009
14,142
We want to measure the power of the two antennas

antennas don't have/produce power

As Adam responded tell us much more

but a field strength meter is usually used to determine radiated signal strength

Last edited:

#### (*steve*)

##### ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,508
Or if it's the received signal strength you want to measure, provide a fixed gain to both, and compare the amplitude of the signals.

Assuming the antennas have the same impedance, the amplitude week be proportional (not directly) to power. For received signed it's normally about the amplitude (possibly in uV) than the received power (possibly in uW) anyway.

#### thanhvu94

Oct 1, 2016
3
@adam, davenn: Sorry for my confusing question. Just like davenn mean, my professor says that the idea of our project is just to measure and compare the signal strength from 2 antennas to choose which one receive better signal (We will control the aquatic drone from a riverbank). But my team is new to RF so we don't have much idea to discuss.

Thank you.

#### thanhvu94

Oct 1, 2016
3
Or if it's the received signal strength you want to measure, provide a fixed gain to both, and compare the amplitude of the signals.

Assuming the antennas have the same impedance, the amplitude week be proportional (not directly) to power. For received signed it's normally about the amplitude (possibly in uV) than the received power (possibly in uW) anyway.

Thank you for your reply, can you be tell me which tool/circuit/module we can possibly use to measure that?

#### (*steve*)

##### ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,508
Is this to compare antennas and then decide which one to use, or will the device have multiple antennas that it will dynamically chose from?

If the former, you could simply try them one by one and see which one allows reliable control at the longest range.

Replies
1
Views
613
Replies
8
Views
2K
Replies
7
Views
1K
Replies
6
Views
2K
Replies
4
Views
899