mlab mlab-module comm-rf lna low-noise-amplifier radio rf pream rf-preamp


Very low noise <0.8dB band pass amplifier to multi frequency bands.

This is an open-source hardware design, one of the modules from the MLAB labolatory system.

Low Noise Amplifier LNA01A

Author: Jakub Kákona,


An input low noise amplifier designed for band amplification of signals immediately after the antenna. It is optimized for very low noise to enable the construction of receiver setups with a low noise figure.

LNA01A Bottom View

Technical Parameters

Parameter Value Note
Power Supply Voltage up to +12V max 200mA
Frequency Range 100 - 200 MHz With different components, up to 450MHz
Maximum RF Input Power + 24 dBm Maximum 1V at RF input
OIP3 40dBm
Noise Figure < 0.8 dB

Design Description


The amplifier's circuit is implemented on an FR4 printed circuit board (PCB). The PCB can be equipped with either direct SMA connectors or edge connectors.

Noise Suppression

The amplifier must necessarily be housed in a metal shielding box to prevent it from being excited by signals emitted to the antenna. The metal box also ensures higher signal quality from the amplifier output.

Mechanical Design

It is assumed that the amplifier will be placed in a tin-plated metal shielding box in which the amplifier is soldered behind the connectors. Holes for connectors are created in the box using punching pliers with a diameter tool of 6.35mm. A template named hole_pattern.pdf is used for punching these holes.

Production and Testing

The assembly of SMD components is carried out using solder paste, including the transistor. Special attention must be paid to antistatic protection during the transistor assembly to prevent damage. The transistor can only be soldered using electrostatically safe tools, such as hot air or IR solder.

After soldering the SMD components, an air coil can be soldered, which may be soldered using a contact solder. It is advisable to use a higher power solder to securely solder the coil to the ground plane.

Finally, after fully soldering the coil, the amplifier's input and output can be short-circuited, which are short-circuited by the non-etched copper layer on the opposite side of the SMD components at the PCB factory. Therefore, it is necessary to clear the hole for the SMA connector center, which can best be done with a drill of about 8mm in diameter.