RF / Antenna Frequency Calculator
Calculate frequency, wavelength, and antenna length. Essential for RF design, wireless communication, and IoT antenna sizing.
RF / Antenna Frequency Calculator
Free space: 1.0, Coaxial: 0.66-0.85, Air: 0.95-0.99
Common RF Frequency Bands
| Band | Frequency Range | Wavelength | Common Use |
|---|---|---|---|
| LF (Low Frequency) | 30-300 kHz | 1-10 km | Navigation, AM radio |
| MF (Medium Frequency) | 300 kHz - 3 MHz | 100-1000 m | AM radio, maritime |
| HF (High Frequency) | 3-30 MHz | 10-100 m | Shortwave radio, ham |
| VHF (Very High Frequency) | 30-300 MHz | 1-10 m | FM radio, TV, aviation |
| UHF (Ultra High Frequency) | 300 MHz - 3 GHz | 10 cm - 1 m | TV, cellular, WiFi 2.4GHz |
| SHF (Super High Frequency) | 3-30 GHz | 1-10 cm | WiFi 5GHz, radar, satellite |
| EHF (Extremely High Frequency) | 30-300 GHz | 1-10 mm | Millimeter wave, research |
| ISM 2.4 GHz | 2.4-2.5 GHz | ~12.5 cm | WiFi, Bluetooth, Zigbee |
| ISM 5 GHz | 5.15-5.85 GHz | ~5-6 cm | WiFi 5GHz, IoT |
| ISM 915 MHz | 902-928 MHz | ~33 cm | LoRa, RFID, IoT |
Formulas
Wavelength from Frequency:
λ = (c × vf) / f
Where: λ = wavelength, c = speed of light (299,792,458 m/s), vf = velocity factor, f = frequency
Frequency from Wavelength:
f = (c × vf) / λ
Antenna Length:
Quarter Wave: L = λ/4
Half Wave: L = λ/2
Full Wave: L = λ
Note: Velocity factor accounts for the speed of electromagnetic waves in different media. Free space uses 1.0, while coaxial cables typically use 0.66-0.85 depending on dielectric material.