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What antennas are used for Wi-Fi?

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Wi-Fi operates in the 2.4 GHz ISM band (2400–2483.5 MHz), the 5 GHz U-NII bands (about 5150–5850 MHz) and, in many countries, the 6 GHz band (5925–7125 MHz in the US). Wi-Fi antennas are dual- or tri-band dipoles, PIFAs, printed and chip antennas in clients, and arrays of dipoles or patches in access points, with several antennas per device for MIMO and beamforming.[1][2][3]

How are dual- and tri-band Wi-Fi antennas made?

Common approaches are dual-branch monopoles or PIFAs with a long arm resonant at 2.4 GHz and a short arm for 5–7 GHz, sleeve dipoles with trap or choke sections, and printed antennas with slots creating a second resonance. Covering 5.15–7.125 GHz in one band requires about 32% bandwidth, which favors broadband monopoles and fat dipoles.[4][5]

How many antennas does a Wi-Fi device need?

Clients usually have two antennas (2×2 MIMO); access points commonly four to eight or more per band. Spacing, polarization and pattern diversity reduce correlation, and explicit beamforming uses channel sounding to steer energy toward clients.[1][6]

What regulatory limits apply?

In the US, 2.4 GHz digital transmission systems are limited to 1 W conducted power with up to 6 dBi antenna gain, with reductions above 6 dBi (1 dB per dB for general use, 1 dB per 3 dB for fixed point-to-point).[3] U-NII limits differ by sub-band and device class.[2] Antennas must be permanently attached or use a unique connector.[7]

Frequently asked questions

Is a higher-gain Wi-Fi antenna always better?

No; it narrows coverage and may require power reduction under the rules.

Why are AP antennas often vertical?

Vertical dipoles give omnidirectional coverage in the horizontal plane.

Does 6 GHz need a different antenna?

It needs coverage up to 7.125 GHz; many older dual-band antennas stop near 5.85 GHz.

References

Online sources accessed October 21, 2026; printed works cited by edition. See all sources.

  1. “IEEE Std 802.11-2020: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications”. IEEE. 2021.
  2. “47 CFR 15.407 — General technical requirements (U-NII devices)”. U.S. FCC, eCFR. current text.
  3. “47 CFR 15.247 — Operation within the bands 902-928 MHz, 2400-2483.5 MHz, and 5725-5850 MHz”. U.S. FCC, eCFR. current text.
  4. “Printed Antennas for Wireless Communications”. R. Waterhouse (ed.), Wiley. 2007.
  5. “Modern Small Antennas”. K. Fujimoto and H. Morishita, Cambridge University Press. 2013.
  6. “Foundations of MIMO Communication”. R. W. Heath Jr. and A. Lozano, Cambridge University Press. 2018.
  7. “47 CFR 15.203 — Antenna requirement”. U.S. FCC, eCFR. current text.
Categories: Applications by band