TABLE OF CONTENTS Microwave engineers design RF circuits and antennas with solutions to Maxwell s equations, which describe mathematically the interaction at a distance between electromagnetic sources (charges and currents) and materials (dielectrics, semiconductors, and conductors) in space and time. Our study of grounding concentrates on the flow of current in a variety of conductors such as wires, printed circuit boards, and antennas. Maxwell s equations help us to understand precisely the behavior of ground currents in these various conducting structures. In this chapter, we review pertinent aspects of electrostatics, magnetostatics, and electromagnetics and solidify the concepts of grounding introduced in Chapter 1.
The field of electrical engineering is vast and necessarily divided into a large number of specialties that are mostly application related. A unifying perspective of electrical engineering focuses on the frequency of the signals that are processed by an electrical component such as DC and low frequency AC (to a few kilohertz), high frequency (3 to 30 MHz), microwave (1 to 30 GHz), and millimeter wave (30 to 300 GHz). In each of these portions of the electromagnetic spectrum, the relationship between the wavelength (light speed divided by frequency) of the electromagnetic signal and the circuit size dictates the necessary design approach. At low frequencies, the dimensions of the circuit are minute compared to a wavelength, so we can ignore the propagating phase delay of the signal and design devices using the rules of lumped circuits. No precisely defined boundary between low and high frequency...
