Radiation Resistance Of Antenna Calculator

Formula Used:

\[ R_{rad} = \frac{2 \times P_r}{i_o^2} \]

Radiation Resistance (R_rad):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Radiation Resistance?

Radiation Resistance is the effective resistance of an antenna that represents the power radiated into space as electromagnetic waves. It's a key parameter in antenna design and analysis.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ R_{rad} = \frac{2 \times P_r}{i_o^2} \]

Where:

\( R_{rad} \) — Radiation Resistance (Ohm)
\( P_r \) — Average Power (Watt)
\( i_o \) — Sinusoidal Current (Ampere)

Explanation: This formula calculates the effective resistance that would dissipate the same amount of power as the antenna radiates into space.

3. Importance of Radiation Resistance

Details: Radiation resistance is crucial for antenna efficiency calculations, impedance matching, and determining how much power is actually radiated versus lost as heat in the antenna system.

4. Using the Calculator

Tips: Enter average power in watts and sinusoidal current in amperes. Both values must be positive numbers greater than zero for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What is the relationship between radiation resistance and antenna efficiency?
A: Higher radiation resistance generally indicates better antenna efficiency, as more power is radiated rather than dissipated as heat.

Q2: How does radiation resistance vary with antenna type?
A: Different antenna types (dipole, monopole, loop, etc.) have different characteristic radiation resistance values that depend on their physical dimensions and configuration.

Q3: What are typical values of radiation resistance?
A: For a half-wave dipole, radiation resistance is approximately 73 ohms in free space. Other antenna types have different characteristic resistances.

Q4: How does ground proximity affect radiation resistance?
A: For antennas near ground, radiation resistance can be significantly affected by ground reflections and the electrical properties of the ground.

Q5: Can radiation resistance be measured directly?
A: Radiation resistance is typically calculated from measured radiation patterns and power input, or derived from impedance measurements using network analyzers.