Generic 0.1-2000MHz RF Wideband LNA Board Module, 30dB Gain

The gain of this amplifier module is directly controlled by its DC supply voltage. Operating between 5V and 12V, increasing the voltage increases the gain. This allows you to implement automatic gain control (AGC) in your system by using a microcontroller and a DAC to dynamically adjust the supply voltage based on received signal strength, preventing overload from strong signals or boosting weak ones for optimal receiver performance.

The lower frequency limit is determined by the input and output DC-blocking capacitors on the board. The default capacitors support operation down to 0.1 MHz (100 kHz). To extend operation to even lower frequencies, such as 5 kHz, you must replace the default capacitors with larger values, for example, 10 µF capacitors. This modification lowers the high-pass filter cutoff point, allowing lower frequency signals to pass into the amplifier stage.

For the lowest noise figure and good stability, operate the module with a power supply voltage between 8V and 10V. In this range, the low-frequency end gain can reach up to 30 dB while maintaining optimal noise performance. Operating at 12V provides maximum gain (up to 32.5 dB at low frequencies) but may slightly increase noise figure. Ensure your signal source and load are properly matched to 50 ohms to prevent standing waves that can degrade noise performance.