Receiver Front End

The receiver front end comprises the antenna, amplification, filtering, mixing, and conversion to quantized samples needed to convert received electromagnetic waves at one or more carrier frequencies into digitized waveforms at baseband or an intermediate frequency (IF) for signal processing. In addition, the receiver's oscillator and frequency synthesizer are discussed in this chapter. A variety of technologies are available for implementing each component, and the chapter addresses considerations in their selection and use. It provides subsections on each class of component, describing their key characteristics and parameters, and the uses of different classes of devices. The chapter introduces the important characteristic of a receiver's noise figure, and shows how it is calculated from component characteristics. It also introduces some common alternative architectures for receiver front ends, describing various considerations in their selection.