Chapter Overview
As the use of electronic communication has increased over the years, the frequency spectrum normally used for radio signals has become extremely crowded. In addition, there has been an increasing need for more spectrum space to carry wider-bandwidth video and digital information. One of the primary solutions to this problem has been to move more radio communication higher in the spectrum, specifically the microwave range, the 1- to 300-GHz range.
In the past, because of the difficulty of generating, transmitting, and receiving microwave signals, only those who truly needed and could afford the special equipment used this part of the spectrum. Today, thanks to advances in semiconductor technology, microwaves are now being more widely used. This has opened the microwave spectrum to all sorts of new services which include wireless local-area networks, cellular and cordless phones, digital satellite radio, and wireless broadband, to name a few. In this chapter we take a look at some of the components and techniques used in modern microwave radios.
Chapter Outline
16-1 Microwave Concepts
16-2 Microwave Lines and Devices
16-3 Waveguides and Cavity Resonators
16-4 Microwave Semiconductor Diodes
16-5 Microwave Tubes
16-6 Microwave Antennas
16-7 Microwave Applications
Chapter Objectives
- Explain the reasons for the growing use of microwaves in communications.
- Identify the circuits that require the use of special microwave components.
- Define the term waveguide, explain how a waveguide works, and calculate the cutoff frequency of a waveguide.
- Explain the purpose and operation of direction couplers, circulators, isolators, T sections, cavity resonators, and microwave vacuum tubes.
- Describe the operation of the major types of microwave diodes.
- Name five common types of microwave antennas and calculate the gain and beam width of horn and parabolic dish antennas.
- Explain the basic concepts and operation of pulsed and Doppler radar.