High Frequency (HF)
Shortwave broadcasting · Amateur radio · Aviation HF comms
| Frequency Range | 3–30 MHz |
| Wavelength | 10–100 m |
| ITU / Standard | ITU Band 7 |
Applications
- →Shortwave broadcasting
- →Amateur radio
- →Aviation HF comms
- →Over-the-horizon radar
- →RFID (13.56 MHz)
Propagation Characteristics
Ionospheric skip enables long-distance propagation. NVIS (Near Vertical Incidence Skywave) used for regional comms. Skip distance varies with solar activity and time of day.
Regulatory Notes
Licensed use in most regions. 13.56 MHz is a global ISM frequency. Amateur allocations at 3.5, 7, 10, 14, 18, 21, 24, 28 MHz.
Related Calculators
Wavelength / Frequency
Convert between frequency, wavelength, and wave number in free space or medium. Calculate half-wave and quarter-wave lengths for antenna and transmission line design.
Free-Space Path Loss
Calculate free-space path loss (FSPL) using the Friis transmission equation for wireless link budget analysis
Dipole Antenna
Calculate the physical length, wavelength, gain, radiation resistance, and 50Ω VSWR for a half-wave dipole antenna at any frequency. Supports velocity factor for insulated wire.