- dBi Range Calculator 有助于确定 effective range of an antenna based on its gain (dBi), frequency, and transmitted 功率. This tool is crucial in wireless communication, radio frequency (RF) engineering, and antenna design, where signal coverage is a 键 因子。
This calculator is useful in:
- Wi-Fi network planning – Determining signal reach for routers
- Satellite and radio communications – Evaluating signal loss over distance
- Drone and UAV telemetry – Ensuring stable long-range communication
- RF and microwave engineering – Optimizing antenna design for better coverage
通过计算 free-space path loss (FSPL), the tool helps users optimize antenna placement, maximize signal coverage, and improve communication efficiency.
Formula for Dbi Range Calculator
The range of an antenna is influenced by:
- 天线增益 (dBi) – A measure of how well an antenna focuses energy
- Transmission Frequency (Hz) – Higher frequencies experience more loss
- 距离（米） – The greater the distance, the weaker the received signal
- Free-Space Path Loss (FSPL) Formula is used to estimate signal loss over distance:
FSPL Formula
FSPL (dB) = 20 × log10(Distance) + 20 × log10(Frequency) + 20 × log10(4π / c)
地点：
- 距离（米） = The range to calculate
- 频率（Hz） = Transmission frequency
- c = 3 × 10⁸ m/s = 速度 的光
- 4π = Spherical wavefront expansion
Rearrange for Distance
计算 最大传输距离， 我们用：
Distance (m) = 10^((dBi - FSPL) / 20) × Reference Distance
This formula helps estimate how far a signal can travel before becoming too weak for reliable communication.
Reference Table – Antenna Range Estimations
For ease of use, here’s a 参考表 showing estimated transmission distances for different antenna gains at 2.4 GHz (Wi-Fi frequency):
| 天线增益 (dBi) | Distance (Meters) | Distance (Kilometers) |
|---|---|---|
| 0 dBi (Omni) | ~100 m | 0.1公里 |
| 3 dBi (Dipole) | ~250 m | 0.25公里 |
| 6 dBi | ~500 m | 0.5公里 |
| 9 dBi | ~1,000 m | 1.0公里 |
| 12 dBi | ~2,000 m | 2.0公里 |
| 15 dBi | ~4,000 m | 4.0公里 |
| 20 dBi | ~10,000 m | 10.0公里 |
请注意： These values assume ideal free-space conditions with no obstacles. Actual range may vary due to interference, obstructions, and atmospheric conditions.
Example of Dbi Range Calculator
1. Calculate Range for a 9 dBi Antenna at 2.4 GHz
使用 FSPL formula:
FSPL = 20 × log10(Distance) + 20 × log10(2.4 × 10⁹) + 20 × log10(4π / 3 × 10⁸)
Rearrange for Distance:
Distance = 10^((9 - FSPL) / 20) × Reference Distance
Approximating, we get 1 km (1,000 meters) for a 9 dBi antenna at 2.4 GHz in free-space conditions.
2. Calculate Range for a 15 dBi Antenna at 5 GHz
For a 15 dBi antenna operating at 5 GHz, the increased frequency results in higher path loss, reducing range. Using the same formula, the estimated range is around 2 km.
最常见的常见问题解答
dBi (decibels relative to an isotropic radiator) measures how much an antenna amplifies signals in a specific direction compared to a perfect spherical radiator. Higher dBi means greater directional focus and longer range.
Higher frequencies experience greater path loss 由于增加 atmospheric absorption and material penetration losses, making long-distance communication harder.