Home
Back
Friis Formula:
| From: | To: |
The Friis transmission formula is used in telecommunications engineering to calculate the power received in an antenna from another antenna under ideal conditions. It provides the path loss between transmitter and receiver in free space.
The calculator uses the Friis formula:
Where:
Explanation: The formula calculates free-space path loss in decibels (dB), which represents signal attenuation between two antennas in an unobstructed path.
Details: Path loss calculation is essential for wireless communication system design, helping engineers determine appropriate transmitter power, antenna gain, and receiver sensitivity for reliable communication links.
Tips: Enter frequency in Hertz and distance in meters. Both values must be positive numbers. The calculator will compute the path loss in decibels (dB).
Q1: What is free-space path loss?
A: Free-space path loss is the attenuation of radio energy between two antennas in free space (no obstacles), caused by the spreading of radio waves in space.
Q2: Why does path loss increase with frequency?
A: Higher frequency signals have shorter wavelengths, which results in greater spreading loss and more significant attenuation in the propagation medium.
Q3: What are typical path loss values in real-world scenarios?
A: While this calculator shows ideal free-space loss, real-world environments typically have higher losses due to obstacles, reflections, and other propagation effects.
Q4: How accurate is the Friis formula?
A: The formula provides accurate results for line-of-sight propagation in free space but doesn't account for real-world factors like terrain, buildings, or atmospheric conditions.
Q5: Can this formula be used for satellite communications?
A: Yes, the Friis formula is commonly used in satellite link budget calculations where free-space conditions largely apply.