The Low-Noise Block Downconverter (LNB) is a critical component in satellite reception, converting high-frequency signals from the satellite to lower frequencies that can be processed by the receiver.
Here’s a list of common LNB frequencies used in satellite communications:
Common LNB Frequency Ranges
1. C-Band LNB Frequencies
- Input Frequency: 3.7 to 4.2 GHz
- Output Frequency: 950 to 1450 MHz
- LO (Local Oscillator) Frequency: 5.15 GHz
- Polarization: Linear
C-Band is widely used for satellite television and internet services in areas with high rainfall as it is less susceptible to rain fade.
2. Ku-Band LNB Frequencies
- Standard Ku-Band:
- Input Frequency: 10.7 to 12.75 GHz
- Output Frequency: 950 to 2150 MHz
- LO Frequencies:
- Low Band: 9.75 GHz (for 10.7 to 11.7 GHz input)
- High Band: 10.6 or 10.75 GHz (for 11.7 to 12.75 GHz input)
- Polarization: Linear or Circular
- Extended Ku-Band:
- Input Frequency: 12.25 to 12.75 GHz
- Output Frequency: 950 to 1450 MHz
- LO Frequency: 11.3 GHz
- Polarization: Linear or Circular
Ku-Band is popular for direct-to-home (DTH) satellite television and certain types of satellite internet services.
3. Ka-Band LNB Frequencies
- Input Frequency: 18.3 to 22.2 GHz
- Output Frequency: 950 to 2150 MHz
- LO Frequencies:
- 19.2 GHz (for 18.3 to 19.2 GHz input)
- 20.2 GHz (for 19.2 to 20.2 GHz input)
- 21.2 GHz (for 20.2 to 21.2 GHz input)
- Polarization: Linear
Ka-Band is increasingly used for high-speed satellite internet services due to its ability to provide higher bandwidth.
4. X-Band LNB Frequencies
- Input Frequency: 7.25 to 7.75 GHz
- Output Frequency: 950 to 1450 MHz
- LO Frequency: 6.3 GHz
- Polarization: Linear
X-Band is primarily used for military, governmental, and weather satellite communications.
5. S-Band LNB Frequencies
- Input Frequency: 2.5 to 2.7 GHz
- Output Frequency: 950 to 1150 MHz
- LO Frequency: 1.55 GHz
- Polarization: Linear
S-Band is utilized for satellite communication in mobile services, including satellite radio and certain regional communication systems.
Key Points to Remember
- LO Frequency: The Local Oscillator (LO) frequency is used to mix with the input frequency to produce the lower output frequency, which the receiver processes.
- Polarization: LNBs can support linear (horizontal and vertical) or circular (right-hand or left-hand) polarization, depending on the satellite signal.
- Output Frequency: This is the down-converted frequency that the satellite receiver can handle, typically within the L-band range (950 to 2150 MHz).
Summary Table
| Band | Input Frequency Range | Output Frequency Range | LO Frequency(s) | Polarization |
|---|---|---|---|---|
| C-Band | 3.7 – 4.2 GHz | 950 – 1450 MHz | 5.15 GHz | Linear |
| Ku-Band | 10.7 – 12.75 GHz | 950 – 2150 MHz | 9.75 / 10.6 / 10.75 GHz | Linear / Circular |
| Extended Ku-Band | 12.25 – 12.75 GHz | 950 – 1450 MHz | 11.3 GHz | Linear / Circular |
| Ka-Band | 18.3 – 22.2 GHz | 950 – 2150 MHz | 19.2 / 20.2 / 21.2 GHz | Linear |
| X-Band | 7.25 – 7.75 GHz | 950 – 1450 MHz | 6.3 GHz | Linear |
| S-Band | 2.5 – 2.7 GHz | 950 – 1150 MHz | 1.55 GHz | Linear |
Choosing the Right LNB
The choice of LNB depends on:
- The frequency band used by your satellite service.
- The required polarization type.
- The specific frequency range of the satellite signal.
- Your receiver’s capability to process the output frequency.