Talk:Low-noise amplifier

Design section and generally

The description of S-parameters and many other factors is badly confused. I'm not expert enough to fix this, but I know enough to see that what's there is wrong. — Preceding unsigned comment added by ChrisMaple (talk • contribs) 02:48, 2 November 2011 (UTC)

The article seems to be very focused on *using* Low Noise Amplifiers in a *single application*, satellite communication. Yet compared to, for example the Instrumentation amplifier, it offered me very little explanation of what an LNA is, how it works, its key properties, and how they would be best applied outside the one application. I am not expert enough to write that content. However I do think the start of the article should have a section modelled on something like Instrumentation amplifier. I read that first to compare the two types of amplifiers, mostly understood enough on the first reading to then move to this LNA article. The LNA article didn't help me. I have a bit of background in electronics. I was trying to research an answer to a question on electronics.stackexchange. This LNA article did not help because the application in the ee.se question has nothing to do with satellite communications. It don't feel the LNA article would have helped if I were looking for satellite communication design information either because there is little specific or concrete information.

While not ideal, maybe a survey of 4+ different manufacturers different LNA products and application notes might help provide some structure and references? --Gbulmeruk (talk) 13:38, 29 August 2014 (UTC)

This article is written VERY poorly and should be suppressed. It seems written by a student with very poor understanding of the topic. I fixed one section that is now about the device models used for simulations and was previously about the (physical?) nature of the employed devices. Major issues of this kind are all over the article and it would be best to suppress it entirely, as fixing it would require a bigger effort than rewriting it from scratch. [User: corradocarta 1 September 2015] — Preceding unsigned comment added by Corradocarta (talk • contribs) 13:01, 1 September 2015 (UTC)

Yes, the article needs a lot of work. Fundamentally, it is confused about its subject. There is a notion of low noise design that only sees low-level signal. Small signal models are appropriate, and intermodulation can be ignored because the signals are small. When the design must also confront intermodulation (i.e., large signal distortion products), then other methods are used. The article also focuses on communications, but low noise circuits are also needed when making measurements. Glrx (talk) 17:44, 4 September 2015 (UTC)

In the case of communications systems, especially satellite systems, transmitter power is fundamentally limited, and so receiver noise figure is of fundamental importance. I suspect that is why they have the WP:COMMONNAME of LNA. In the case of Instrumentation amplifier, it isn't quite as fundamental. Certainly low noise is a property of better ones, but that makes them more expensive. That is a trade-off that buyers need to make. Also for stereo amplifiers, where everyone wants less noise, but other considerations are also important. No-one calls their stereo amplifier LNA, and I suspect not so often for instrumentation amplifier. In some case tolerance on gain might be more important for an instrumentation amplifier, so one can make accurate signal amplitude measurements. In measuring the output power of a radio transmitter, noise is not so important. Gah4 (talk) 19:25, 17 September 2019 (UTC)

Section: LNA design premise is false

(This is my very first article to edit. Please forgive my wikignorance in advance. Since I am new as an editor I will watch this article to see how someone with a higher wikIQ would make the suggestion or correction. Thanks!)

First I am not an expert on this topic. My contention of this section's false premise:

Low noise amplifiers are the building blocks of any communication system.

is that there is no documentation that smoke signals or handwriting required LNAs in their design. So for the non-expert like myself I would suggest you remove the words "any communication system" and replace it with the appropriate type of communication system. Zerostatetechnologies (talk) 00:15, 29 April 2016 (UTC)

Changed

Low noise amplifiers are the building blocks of any communication system.

to

Low noise amplifiers are the building blocks of certain, unspecified systems.

regarding my previous comment about the global generalization of "any". Please tweak my correction or let me know if I'm doing this correctly. Thanks in advance. Zerostatetechnologies (talk) 00:15, 29 April 2016 (UTC)

Zerostatetechnologies (talk) 23:41, 24 December 2015 (UTC)

References

This article has many problems. Its focus is on electronic communications, but that is not the only area where low-noise amplifiers are used. Glrx (talk) 20:59, 27 December 2015 (UTC)

Feel free to correct this hyperbole/inaccuracy. Otherwise I wil do it myself within a week. Andries (talk) 10:00, 29 December 2015 (UTC)

Feel free to add more uses. What other problems? Andries (talk) 10:00, 29 December 2015 (UTC)

In some communications systems, one can arrange that there is enough power that amplifier noise is not the limiting consideration. Increasing transmitter power reduces the need for amplification in the receiver, and makes it easier to stay above the thermal noise level. For satellites, with power limited by the solar array size, that pretty much never happens. In many other cases, transmitter power can be increased if necessary. Among others, improvements to the Applications section might help. Gah4 (talk) 19:12, 17 September 2019 (UTC)

Applications

There is a {{cn}} on the satellite communications part of the Applications section. There is a fundamental problem with {{cn}} in that we don't know if it applies to the preceding term, whole sentence, or whole paragraph. Those who add them are supposed to indicate on the talk page the reason, but rarely do that. It seems to me that satellite communications is one place where it is obvious, that one never has too much signal. But the other items are not so obvious. Any thoughts to fixing this? Gah4 (talk) 19:07, 17 September 2019 (UTC)

Gah4, {{Citation needed span}} ~Kvng (talk) 19:08, 23 August 2021 (UTC)

Pretty neat. Now all we have to do is get people to use them. Gah4 (talk) 21:19, 23 August 2021 (UTC)

@Gah4: If you can't figure out what is being requested, it's OK to WP:BOLDLY remove the tag. ~Kvng (talk) 14:28, 27 August 2021 (UTC)

Yes, sometimes I do that. If I am in the right mood, also mention it on the talk page, where it could have been mentioned earlier. Sometimes I want to see what others say, though. Gah4 (talk) 23:38, 27 August 2021 (UTC)

noise figure and noise temperature

This article has very little about noise figure, though some links to it, and none about noise temperature. Considering that LNAs are often specified by noise temperature, it seems that would be useful to mention. Gah4 (talk) 19:52, 17 September 2019 (UTC)

India Education Program course assignment

This article was the subject of an educational assignment supported by Wikipedia Ambassadors through the India Education Program.

The above message was substituted from {{IEP assignment}} by PrimeBOT (talk) on 20:07, 1 February 2023 (UTC)