Overview

As pointed out in Chapter 1, the basic building blocks of an SSB communication system include the transmitter, the receiver, and the antenna. For many purposes, these are adequate for satisfactory communication. For more complex systems, additional specialized equipment supplement these basic components. Following this chapter, we cover specialized topics in transmitter and receiver design, such as transceivers, exciters, power amplifiers, filters, speech processing, and frequency standards, as well as other system elements such as preselectors, postselectors, and antenna couplers. When other than analog speech is to be transmitted, a modulator/demodulator (modem) is required as well, but this subject has become quite specialized and is beyond the scope of this book.

Preselectors and postselectors, discussed in Chapter 9, are often required in a system when simultaneous operation (SIMOP) is required of a collocated transmitter and receiver. A preselector may also be necessary if receiver operation is required in close proximity to an unrelated nearby transmitter operating in the same frequency range. When the antenna impedance varies widely over the operating band, a transmitting antenna coupler is required to present a more constant load impedance to the power amplifier.

The purpose of this chapter is not to discuss the system elements, but to describe important topics in system design and analysis. Section 2.1 starts with the basic voice signal that is to be transmitted. The nature of speech and hearing is reviewed, and speech intelligibility and the articulation index...