Carrier Frequency Calculator
Calculate carrier frequency from wavelength or period, or solve for wavelength from carrier frequency. Include velocity factor to account for propagation in coax, cable, or fiber.
What Is Carrier Frequency?
A carrier frequency is the base frequency of a wave used to transport information. In radio, communication systems, and signal processing, this “carrier” gets modulated by voice, data, video, or telemetry. The better you understand the carrier, the easier it is to design antennas, choose channels, and evaluate transmission quality.
Core equations used by this calculator
- f = v / λ (frequency from wavelength)
- λ = v / f (wavelength from frequency)
- f = 1 / T (frequency from period)
- v = c × VF where c is the speed of light and VF is velocity factor
How to Use the Carrier Frequency Calculator
1) Pick a calculation mode
Choose whether you want to solve for frequency or wavelength, or derive frequency from a known period.
2) Set the medium or velocity factor
If the signal travels in free space, VF is close to 1. If it travels through coax or twisted-pair cable, VF can be much lower and materially changes wavelength and phase relationships.
3) Enter your value and unit
You can work in common units (Hz, kHz, MHz, GHz, THz or m, cm, mm, µm, nm), and the calculator handles conversion automatically.
Worked Examples
Example 1: Frequency from wavelength in air
If wavelength is 2 meters and propagation is in air (VF ≈ 0.9997), the carrier frequency is roughly 149.8 MHz.
Example 2: Wavelength in coax at 915 MHz
For a 915 MHz signal in PE coax (VF = 0.66), wavelength is much shorter than free-space wavelength. This matters when cutting transmission lines and designing matching sections.
Example 3: Frequency from period
A period of 10 ns corresponds to 100 MHz, because f = 1 / T.
Typical Carrier Frequency Ranges
- AM broadcast: roughly 530 kHz to 1.7 MHz
- FM broadcast: 88 MHz to 108 MHz
- Wi-Fi (common): 2.4 GHz and 5 GHz bands
- Cellular systems: from hundreds of MHz to several GHz depending on band
- Satellite and radar: often GHz to tens of GHz
Common Mistakes to Avoid
- Using free-space speed when your signal is inside cable or dielectric material.
- Mixing MHz and GHz without converting units correctly.
- Confusing carrier frequency with modulation bandwidth.
- Forgetting that wavelength shrinks as frequency increases.
Quick FAQ
Is carrier frequency the same as bandwidth?
No. Carrier frequency is the center/base frequency of the wave. Bandwidth is the range of frequencies occupied by the modulated signal.
Can I use this for optical frequencies?
Yes. Use THz for frequency or nm/µm for wavelength, and choose an appropriate velocity factor if the wave is in a medium.
Does this replace full RF design software?
No. It is ideal for quick calculations, checks, and educational use. Complex systems still need detailed simulation and measurement.