5.14 LOOKING AHEAD

Chapters 2 to 5 established the engineering foundations needed for the remainder of this book: signals, modulation, propagation, and antennas. The emphasis now shifts from how an RF system operates to how its emissions may produce exposure and dose.

Chapter 6 distinguishes emissions, exposure, and dose; surveys natural and human-made RF sources; and introduces the circumstances in which workers and members of the public may encounter RF fields. The antenna concepts developed here—radiated power, gain, beam direction, sidelobes, polarization, duty cycle, and field region—provide the physical starting point for that analysis.

Later chapters then examine interaction with biological systems, practical exposure assessment, exposure standards, and RF radiation safety plans. The central question changes from whether sufficient RF energy reaches a receiver to whether the electric field, magnetic field, power density, or absorbed energy at an accessible location remains within the applicable limits.