How are mmWave antennas designed?

Millimeter-wave antennas operate in the 30–300 GHz range (and in practice the 24–100 GHz bands used by 5G FR2, automotive radar and satellite links). Because a fixed-gain antenna’s aperture shrinks with λ², mmWave systems use compact high-gain phased arrays, often integrated in the same package as the RF IC (antenna-in-package, AiP), to recover link margin and steer around blockage.^[1][2]

Which 5G mmWave bands are used?

3GPP FR2 originally spans 24.25–52.6 GHz, with bands such as n257 (26.5–29.5 GHz), n258 (24.25–27.5 GHz), n260 (37–40 GHz) and n261 (27.5–28.35 GHz); Release 17 added FR2-2 up to 71 GHz.^[2]

What changes at mmWave?

• λ is millimeters: element spacing λ/2 at 28 GHz is about 5.4 mm, so a 4×4 array fits in about 2 cm × 2 cm.
• Transmission-line and dielectric losses rise; feed lines must be very short, which drives AiP integration.
• Manufacturing tolerances, via transitions and package substrates matter to tens of micrometers.
• Human body, hand and even foliage blockage are severe, so phones use several modules on different sides.^[1]

How are mmWave arrays tested?

Because antennas are integrated with RF ICs, there are often no connectors: performance is measured over the air, including EIRP, EIS and beam management, in compact antenna test ranges or near-field systems specified by 3GPP.^[2] See OTA testing and compact ranges.

Frequently asked questions

See also

• Phased arrays
• Beamforming
• Atmospheric attenuation
• OTA testing

References

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

1. “Millimeter Wave Mobile Communications for 5G Cellular: It Will Work!”. T. S. Rappaport et al., IEEE Access, vol. 1, pp. 335-349. 2013.
2. “3GPP TS 38.101-1 and 38.101-2: NR User Equipment radio transmission and reception (FR1 and FR2)”. 3GPP. current release.