TABLE OF CONTENTS Amplification is a fundamental signal processing operation performed in any wireless communication system. Amplification is needed both in the transmitters and receivers. However, each amplifier has its own set of requirements and design criteria. In section 10.2, we talk about the general principles of amplifier design.
In the receiver, the amplifier is required to amplify a very weak signal that is buried in noise and interference, with the amplifier adding a minimum amount of noise so that the signal can be detected by the following signal processing stages. Low noise and amplifier gain are important parameters for determining the amplifier s performance. Low noise amplifiers are presented in section 10.3. Automatic gain control (AGC) amplifiers are also used in the receiver s amplification chain. These amplifiers are placed after the low noise amplifiers, and usually after down converting the received signal to an intermediate frequency. The purpose of the AGC amplifiers is to compensate for the variable attenuation of the wireless channel, so that the output of the amplifier has a constant root mean square (RMS) value. AGC amplifiers are presented in section 10.4.
On the other hand, in the transmitter, the signal is amplified to a sufficient level so that after it becomes attenuated, as it travels through the wireless channel, and noise and interference are added to it, the signal can still be detected at the receiver. Power amplification capabilities, power efficiency and linearity are important parameters for determining the amplifier s performance. Power amplifiers are presented in section...
