Received Power Calculator For Employees

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):

Unit Converter ▲

Unit Converter ▼

From:	To:

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, given the transmitted power, antenna gains, wavelength, and 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:

\( P_t \) — Transmitted power (W)
\( G_t \) — Transmit antenna gain (dB)
\( G_r \) — Receive antenna gain (dB)
\( \lambda \) — Wavelength (m)
\( d \) — Distance between antennas (m)

Explanation: The equation accounts for free-space path loss and the gains of both transmitting and receiving antennas to determine the power received at the destination.

3. Importance of Received Power Calculation

Details: Accurate received power calculation is crucial for wireless communication system design, link budget analysis, and ensuring reliable signal transmission over various 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 numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is free-space path loss?
A: Free-space path loss is the attenuation of radio energy between two antennas due to the spreading of the wavefront in free space, proportional to the square of the distance.

Q2: How do I convert between dB and linear gain values?
A: Linear gain = 10^(dB/10). The calculator automatically converts dB gains to linear values for the calculation.

Q3: What are typical values for antenna gains?
A: Isotropic antennas have 0 dB gain. Directional antennas typically range from 3-24 dB gain, depending on their design and application.

Q4: Does this equation account for environmental factors?
A: No, the Friis equation assumes free space propagation without obstacles, reflection, or atmospheric effects. Real-world calculations may require additional factors.

Q5: How does wavelength relate to frequency?
A: Wavelength (λ) = speed of light (c) / frequency (f). For radio waves, c ≈ 3×10^8 m/s, so λ ≈ 300/f (MHz) meters.