As the "front end" of the receiver channel, it must capture and amplify a very-low-power, low-voltage signal plus associated random noise which the antenna presents to it, within the bandwidth of interest.
All the general factors about the signal are known, such as amplitude, modulation, shape, duty cycle, and more. Despite this apparent simple functional situation, the PA has performance challenges as well. The duplexer uses phasing and phase-shifting to steer the PA's output power to the antenna while blocking it from the LNA input, to avoid overload and saturation of the sensitive LNA input.
Skip to content amplifier RF I saw a comparison of two similar radio receiver modules. It only takes a minute to sign up. Connect and share knowledge within a single location that is structured and easy to search. I saw a comparison of two similar radio receiver modules. The PA stands for power amplifier, in this case a RF or microwave amplifier used for transmission of a signal.
LNA stands for low noise amplifier, normally used for high RF bands or microwave signals as a sensitive signal receiver. PAs and LNAs are not always combined. It depends on the application. I found this article on the web which covers the basic details. However, that is where their commonality ends. Although both have very simple functional block diagrams and roles in principle, they have very different challenges, priorities, and performance parameters.
As the "front end" of the receiver channel, it must capture and amplify a very-low-power, low-voltage signal plus associated random noise which the antenna presents to it, within the bandwidth of interest. All the general factors about the signal are known, such as amplitude, modulation, shape, duty cycle, and more. Despite this apparent simple functional situation, the PA has performance challenges as well.
The duplexer uses phasing and phase-shifting to steer the PA's output power to the antenna while blocking it from the LNA input, to avoid overload and saturation of the sensitive LNA input. PA and LNA will be at opposite ends of an RF link - and in a duplex link the role switches depending on the direction of the signal. The two components along with the 2 antennas do a long way to determining the link-budget, this affects the combination of transmit range and bit rate. At the receive end, for a given modulation scheme and acceptable error rate, you will need a specific ratio of signal power to noise power.
Signal power is determined by transmit power from the PA , antenna gain, and transmission loss. LNA amplifies both the wanted signal, and the thermal noise at the LNA input, plus a little more noise. For a good LNA, this will be around 1dB of extra thermal noise. The LNA also needs to be linear to avoid distortion caused by unwanted often strong signals that can be filtered out later in the receive chain. A good LNA is the first thing to invest in, this buys you dB fairly easily.
Then good antennas, then finally a more powerful PA. Welcome to EDAboard. To participate you need to register.
Registration is free. Click here to register now. Register Log in. JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding. You are using an out of date browser. It may not display this or other websites correctly. You should upgrade or use an alternative browser. The differences between low noise amplifier, power amplifier and opamp. Thread starter lokesh anand Start date Feb 3, Status Not open for further replies.
LNA,PA,Opamp OpAmp is a differential amplifier with a high open-loop gain, high input and low output impedances, which is the optimum for building analog signal processing blocks, such as integrators, amplifiers, filters, instrumentation amplifiers, gyrators, etc.
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