Received Power Calculator For Computer

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 is a fundamental formula in telecommunications that calculates the power received by an antenna from another antenna some distance away. It's essential for designing wireless communication systems and predicting signal strength.

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 accounts for free-space path loss, which increases with distance and decreases with wavelength (higher frequency).

3. Importance of Received Power Calculation

Details: Accurate received power calculation is crucial for wireless system design, link budget analysis, determining communication range, and ensuring reliable signal reception in various applications including WiFi, cellular networks, and satellite communications.

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 and valid.

5. Frequently Asked Questions (FAQ)

Q1: What is the significance of the wavelength parameter?
A: Wavelength is inversely proportional to frequency. Higher frequencies (shorter wavelengths) experience greater path loss, resulting in lower received power at the same distance.

Q2: How are dB gains converted to linear scale?
A: dB gains are converted using the formula: G_linear = 10^(G_dB/10). This conversion is necessary for the mathematical calculation.

Q3: What are typical values for antenna gains?
A: Isotropic antennas have 0 dB gain. Directional antennas can range from 3-24 dB, with highly directional antennas reaching up to 30+ dB gain.

Q4: What are the limitations of the Friis equation?
A: The equation assumes free-space propagation, perfect antenna alignment, polarization matching, and no obstructions, reflections, or multipath effects.

Q5: How does distance affect received power?
A: Received power decreases with the square of the distance (inverse square law). Doubling the distance reduces received power to one-fourth.