Chapter 3. Basic System Components

This chapter begins by presenting block diagrams of the components that comprise the two basic building blocks in all wireless systems: transmitters and receivers. Once you understand how transmitters and receivers work, and the roles they play, you are well on your way to understanding wireless communications. And the good news is, both of these building blocks are fairly simple to look at and to understand because they consist of just five different RF components, which are covered in this chapter.

This chapter explains what roles antennas, amplifiers, filters, and mixers play in changing the nature, size, shape, and frequency of RF signals. It also points out where RF signals come from in the first place: sources. Each section within this chapter demonstrates that these five fundamental components all come in different variations, to accomplish very specific objectives. This usually involves manufacturing the device in such a way as to optimize one or two key performance parameters, which naturally increases its price. Appendix B is a comprehensive list of the many parameters used to quantify RF component performance.

Manufacturers in the RF industry are always trying to improve these five components by making them smaller, lighter, more energy efficient, and at lower cost. High volume wireless products, like cellular phones, have increased the demand for these items, which has served to drive down their cost dramatically. State of the art is constantly changing for these items, as competition spurs innovation. For instance, there are at least 30 companies that manufacture high power amplifiers for wireless infrastructure, which will ultimately translate to lower prices and more features for you, the consumer.

Finally, this chapter concludes with a review of the two basic building blocks just to make sure you were paying attention.