What are the differences between power amplifiers, low noise amplifiers, RF amplifiers and ordinary amplifiers?
Power amplifier is a relatively broad definition: its function is to increase the power of the signal, that is, the output signal power dao is greater than the input signal. Of course, the definition of "large" for 1653 power in 4102 is different in different applications.
The signal amplified by the power amplifier determines the difference of the power amplifier itself. For example, the power amplifier used in audio is an audio power amplifier, and the power amplifier that amplifies the radio frequency (about 1MHz~1000MHz) signal is called the radio frequency power amplifier, and so on.
Amplifier is a broader definition. All devices whose output is larger than the input can be called amplifiers. The so-called common depends on the common law. There are hundreds of amplifiers for different applications. The most commonly used transport amplifier in low-frequency analog signals generally amplifies voltage or current without transmitting power (energy).
A low noise amplifier refers to an amplifier circuit with a very low amplifier noise figure (for example, less than 1dB). In the field of radio frequency and microwave, it is necessary to make the best match for the noise figure, and sacrifice the gain and power transfer characteristics. The concept of noise figure can be Baidu or read textbooks.