Low Noise Amplifiers

Low Noise Amplifiers, also known as (LNA) are an electronic device that amplifies signals of a very low strength from the input source like an antenna where the signals are barely recognizable and need to be amplified with the addition of noise-that without degrading the signal to noise ratio (SNR). LNA’s are designed to minimize the additional noise.

Basic function of a Low Noise Amplifier: Its basic function is to boost the input signal to an appropriate level above the noise floor, so that it can be used for further or additional processing. LNA is the part of an amplifier/receiver that intercepts the incoming signal first hand and therefore plays a vital part in the electronic communication process.

Low Noise Amplifiers use low noise components and circuit topologies. All this is done while keeping in mind the other objectives like power gain and impedance matching.

Well-designed LNAs have a low NF-1 dB, for e.g.-enough to boost the signal-e.g. 10 dB-and a large enough inter-modulation and compression point-IP3 and P1dB-to get the required output from it. Further important specification and parameter of a good LNA is its operating bandwidth, gain flatness, stability, input and output voltage standing wave ratio (VSWR).

LNA should be used keeping it close to the signal source due to which the noise from the subsequent stages of the receiving chain is reduced as a result of signal gain created by the LNA.

The Work done by Low Noise Amplifier enables optimum retrieval of the desired signal in the later stages of the system.

Use of Low Noise Amplifiers:

  • – LNA is extensively used in radio communication
  • – All electronic testing equipment.
  • – It is used in all radio receiving sets of various types.

A full range of LNA’s are available from Raditek website.