Microwave Link Budget Calculator
Here’s a comprehensive table summarizing all you need to know about Microwave Link Budget calculations:
| Parameter | Symbol | Unit | Description |
|---|---|---|---|
| Transmitter Power | P_TX | dBm | Output power of the transmitter |
| Transmitter Antenna Gain | G_TX | dBi | Gain of the transmitting antenna |
| Transmitter Losses | L_TX | dB | Losses in transmitter (cables, connectors, etc.) |
| Free Space Path Loss | L_FS | dB | Loss due to signal propagation in free space |
| Miscellaneous Losses | L_M | dB | Additional losses (fading, polarization mismatch, etc.) |
| Receiver Antenna Gain | G_RX | dBi | Gain of the receiving antenna |
| Receiver Losses | L_RX | dB | Losses in receiver (cables, connectors, etc.) |
| Received Power | P_RX | dBm | Power received at the receiver |
| Receiver Sensitivity | RS | dBm | Minimum power required for successful reception |
| Link Margin | LM | dB | Difference between received power and sensitivity |
| Frequency | f | GHz | Operating frequency of the microwave link |
| Distance | d | km | Length of the microwave link |
| Climate Factor | b | – | Factor accounting for local climate conditions |
| Fade Margin | FM | dB | Additional margin to account for signal fading |
Key Equations:
- Link Budget Equation:
P_RX = P_TX + G_TX – L_TX – L_FS – L_M + G_RX – L_RX - Free Space Path Loss:
L_FS (dB) = 92.45 + 20 log(f) + 20 log(d)
Where f is in GHz and d is in km - Link Margin:
LM = P_RX – RS
Important Considerations:
- A positive link margin (LM > 0) indicates a viable link.
- Typical link margins:
- Excellent: > 20 dB
- Good: 10-20 dB
- Marginal: 0-10 dB
- Poor: < 0 dB
- Include fade margin for reliability in varying weather conditions.
- Consider frequency and space diversity for improved reliability.
- Account for terrain and obstacles in real-world scenarios.
- Comply with local regulations for transmit power and frequency use.
This table provides a comprehensive overview of the key parameters and considerations for microwave link budget calculations. It’s essential to accurately measure or estimate these values to ensure reliable microwave communication links