There are three ways to power a GPIO Labs LNA: Micro USB, the DC header, or a Bias Tee. Which one you should use depends on your setup, not personal preference, so here's how to pick the right one and avoid the most common way these amplifiers get damaged.
Micro USB
Use a micro USB cable with one end connected to a power source like a laptop, a USB power bank, or a wall adapter. A battery or power bank typically provides a cleaner supply than a laptop or mains adapter, which matters more than it sounds, since electrical noise on the power line can show up as noise on your LNA's output.
This is the easiest method to set up and the best choice if you're testing on a bench near a USB power source.
DC Header
Use the DC header on the LNA module if you're powering it from a bench supply or a dedicated power source rather than USB.
Most GPIO Labs LNAs accept a wide input range, typically +5V to +10V on standard models or +3.3V to +20V on our wide-input models, but the 40 dB gain, 8 GHz LNA is the one exception in our lineup and accepts USB power only, not a DC header input.
Bias Tee
Before adding a separate Bias Tee, check whether your receiver already has one built into its input. Many SDR receivers and spectrum analyzers do, in which case your receiver can power the LNA directly with no extra hardware needed.
If your receiver doesn't have a Bias Tee at its input, use a USB Bias Tee to inject DC power onto the same coax cable that's carrying your RF signal, so you don't need a separate power cable running to the LNA at all.
⚠️ Important: Use Only One Method at a Time
Powering the LNA through more than one method at once can damage it. If you're using a Bias Tee, make sure there's no USB cable connected to the USB port and no DC supply connected to the header at the same time. Multiple power sources connected simultaneously can create a voltage conflict at the input that the LNA's internal regulation isn't designed to handle.
Exceeding the rated voltage or connecting power with reversed polarity can permanently damage the amplifier stage. This is the most common way an LNA gets destroyed, especially when powering from a bench supply rather than a pre-made cable, since a bench supply gives you no physical safeguard against wiring it backwards. Double-check both voltage and polarity before connecting power for the first time, and when in doubt, start at the low end of the rated voltage range and confirm correct operation before increasing.
Use a clean DC supply. This matters more on higher gain LNAs, where a noisy power supply can introduce noise directly into the amplified output. If you're seeing unexplained noise on a high-gain LNA, a dirty power supply is one of the first things worth ruling out.
Once your LNA is powered correctly, here's how to get the most out of it: How to Use a Low Noise Amplifier →
