Beamforming Simulator
How an AP with several omnidirectional antennas can steer its signal towards one client, and what that does to everyone else. Watch the waves from each antenna add up at client A and cancel at client B.
How to use this tool controls and what to look for
Turn beamforming on and watch the waves from each antenna meet in step at client A. Then place client B and see what it gets.
Controls to change
- Beamforming: switch between one omni antenna and a beam steered to client A.
- Number of antennas: use 2, 3 or 4 antennas.
- Antenna spacing: set the gap to ½ λ or 1 λ.
- Tap or click the map to place: choose Client A or Client B, then tap or click the map to put it there.
- Move B to a null: put client B where the waves cancel. Move B to a peak puts it where they add up.
- Wave crests: switch the map between Wave crests and the Combined wave.
What to look for
- At client A the waves arrive in step and add up: about +3 dB with two antennas and +6 dB with four.
- Other directions get weaker, and some fall into deep nulls. A client there hears much less than with one antenna.
- With 1 λ spacing, extra beams (grating lobes) appear in other directions.
About this tool
Beamforming lets an access point with several ordinary omnidirectional antennas steer its signal towards one client by adjusting the phase of each antenna. This simulator shows the pattern around the AP, the signal at the client being aimed at, and what happens to another client somewhere else.
What you'll learn
- How phase differences between antennas create a beam
- How much gain beamforming adds: about 3 dB with two antennas and 6 dB with four
- Why other directions can get weaker, down to nulls
- How the AP learns where to aim, using sounding frames
Common questions
Does beamforming increase Wi-Fi range?
A little: the few dB it adds at the client can mean a higher data rate or a slightly longer reach, but it isn't a replacement for good AP placement.
Do I need special antennas for beamforming?
No. Wi-Fi beamforming uses the AP's normal omnidirectional antennas and changes the phase of the signal on each one.
How does the AP know where the client is?
In 802.11ac and later, the AP sends a sounding frame and the client reports how it heard each antenna. The AP uses that to set the phases.
Free for private and educational use. This interactive model is a simplified teaching aid and may contain mistakes. It is provided as is, without warranty. Use it to understand the concepts, not as a substitute for a site survey, vendor documentation or professional design advice.