Received Power Calculator Based On

Friis Transmission Equation:

\[ P_r = P_t \times G_t \times G_r \times \left(\frac{\lambda}{4 \pi d}\right)^2 \]

Transmitted Power (P_t):

Transmit Gain (G_t):

Receive Gain (G_r):

Wavelength (λ):

Distance (d):

Received Power (P_r):

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1. What Is The Friis Transmission Equation?

The Friis transmission equation calculates the power received by an antenna from a transmitting antenna under ideal conditions. It's fundamental in radio communication and radar systems for predicting signal strength at a distance.

2. How Does The Calculator Work?

The calculator uses the Friis transmission equation:

\[ P_r = P_t \times G_t \times G_r \times \left(\frac{\lambda}{4 \pi d}\right)^2 \]

Where:

\( P_r \) — Received power (W)
\( P_t \) — Transmitted power (W)
\( G_t \) — Transmit antenna gain (dB, converted to linear scale)
\( G_r \) — Receive antenna gain (dB, converted to linear scale)
\( \lambda \) — Wavelength (m)
\( d \) — Distance between antennas (m)

Explanation: The equation shows how received power decreases with the square of distance and depends on antenna gains and wavelength.

3. Importance Of Received Power Calculation

Details: Accurate received power calculation is essential for designing wireless communication systems, determining link budgets, and ensuring reliable signal transmission over distances.

4. Using The Calculator

Tips: Enter transmitted power in watts, antenna gains in dB, wavelength in meters, and distance in meters. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What are the assumptions of the Friis equation?
A: The equation assumes free space propagation, antennas in far field, impedance matching, and polarization alignment.

Q2: How does frequency affect received power?
A: Higher frequencies (shorter wavelengths) result in higher path loss, reducing received power for the same distance.

Q3: What is the significance of antenna gain?
A: Antenna gain represents directionality - higher gain antennas focus energy in specific directions, increasing effective power in those directions.

Q4: How accurate is this equation in real-world scenarios?
A: The equation provides ideal results. Real-world factors like obstructions, reflections, and atmospheric conditions require additional considerations.

Q5: Can this be used for satellite communication?
A: Yes, but additional factors like atmospheric attenuation and pointing losses must be considered for accurate satellite link budgets.