Convert frequency ↔ wavelength for any RF/microwave signal, and instantly get quarter-wave (λ/4) and half-wave (λ/2) antenna lengths.
📡 λ = c / f · c = 299,792,458 m/sExample: 3500 MHz (5G n78) → λ ≈ 8.57 cm, quarter-wave ≈ 2.14 cm.
Wavelength is the distance one cycle of a wave travels. In free space it equals the speed of light divided by the frequency:
Quarter-wave and half-wave lengths matter because a monopole antenna is typically λ/4 and a dipole is λ/2. Higher frequency → shorter wavelength → smaller antenna — which is why mmWave 5G arrays are so compact. In a cable or PCB trace multiply by the medium's velocity factor (0.6–0.95).
| Frequency | Wavelength | λ/4 | Use |
|---|---|---|---|
| 700 MHz | 42.8 cm | 10.7 cm | 5G/LTE low-band |
| 2.4 GHz | 12.5 cm | 3.12 cm | Wi-Fi / Bluetooth |
| 3.5 GHz | 8.57 cm | 2.14 cm | 5G n78 mid-band |
| 5 GHz | 6.0 cm | 1.5 cm | Wi-Fi 5/6 |
| 28 GHz | 1.07 cm | 2.68 mm | 5G mmWave n257 |
| 39 GHz | 7.69 mm | 1.92 mm | 5G mmWave n260 |