LNAs are designed to minimize that additional noise, by choosing special components, operating points, and circuit topologies.
Minimizing additional noise must balance with other design goals such as power gain and impedance matching.
An example is a feed line made from 10 feet (3.0 m) of RG-174 coaxial cable and used with a global positioning system (GPS) receiver.
An LNA is a key component at the front-end of a radio receiver circuit to help reduce unwanted noise in particular.
Further specifications are the LNA's operating bandwidth, gain flatness, stability, input and output voltage standing wave ratio (VSWR).
In communication circuits, biasing networks play a critical role in establishing stable operating points for active components, but they also introduce noise.
[3] For instance, in low-noise amplifiers (LNA), the biasing network must be carefully designed to minimize the impact of noise on the overall performance.
Improper biasing can lead to increased noise figures, compromising the signal-to-noise ratio and degrading communication system performance.
The design and selection of components within the bias network are therefore crucial to ensuring low-noise operation, particularly in systems that rely on amplifying weak signals.
[4] In addition, matching networks and careful biasing techniques, such as using low-noise transistors and optimizing impedance matching, help mitigate the noise effects introduced by bias circuits LNAs are used in communications receivers such as in radio telescopes, cellular telephones, GPS receivers, wireless LANs (WiFi), and satellite communications.
SDRs are typically designed to be general purpose and therefore the noise figure is not optimized for any one particular application.