At its core, the Friis Transmission Calculator is a crucial instrument for estimating received power in wireless communication systems. By considering parameters such as transmitted power, antenna gains, wavelength, and the distance between antennas, the calculator offers insights into signal strength. The formula governing this calculation is as follows:
Formula of Friis Transmission Calculator
Pr = Pt * Gt * Gr * (λ / (4πd))^2
Where:
Pr is the received power (in watts, W).
Pt is the transmitted power (in watts, W).
Gt is the gain of the transmitting antenna (dimensionless, typically given in decibels or dBi).
Gr is the gain of the receiving antenna (dimensionless, typically given in decibels or dBi).
λ (lambda) is the wavelength of the signal (in meters, m). It is calculated as the speed of light (c) divided by the frequency (f) of the signal: λ = c / f.
d is the distance between the transmitting and receiving antennas (in meters, m).
General Terms Table
| Term | Description |
|---|---|
| Transmit Power (Pt) | Power of the signal being transmitted. |
| Antenna Gain (Gt, Gr) | Measure of how much an antenna focuses energy. |
| Wavelength (λ) | Distance between identical points in a wave. |
| Distance (d) | Separation between transmitting and receiving antennas. |
This table serves as a quick reference for users, aiding in understanding general terms associated with the Friis Transmission Calculator.
Example of Friis Transmission Calculator
To illustrate the application of the calculator, let’s consider an example. Suppose we have a transmitted power (Pt) of 10 W, transmitting antenna gain (Gt) of 6 dBi, receiving antenna gain (Gr) of 8 dBi, frequency (f) of 2.4 GHz, and a distance (d) of 100 meters. Plugging these values into the formula yields the received power (Pr).
Most Common FAQs
Answer: The frequency is a crucial parameter, often provided by the communication system specifications. It represents the number of cycles per second and is typically measured in Hertz (Hz).
Answer: Yes, the calculator is applicable to various antennas. Ensure you use the correct gain values for the transmitting (Gt) and receiving (Gr) antennas.
Answer: While the calculator is a valuable tool, it assumes free-space conditions and might not account for obstacles or interference in real-world scenarios.