Hertz, or cycles per second, is the basic unit of which of the following characteristics?

The correct answer is frequency. Hertz is defined as the unit of frequency in the International System of Units (SI), representing the number of cycles per second of a periodic phenomenon. When discussing electronic warfare or general electronics, frequency is a crucial characteristic because it relates to how often a signal oscillates or changes state. Knowing the frequency of a signal helps determine its behavior, including how it interacts with other signals and systems.

The other choices, although relevant in the field of electronics, do not represent the fundamental measurement that Hertz signifies. Cycle simply refers to one complete oscillation of a waveform, and while it is related to frequency, it does not measure the rate of oscillation itself. Polarization describes the orientation of the electric field of an electromagnetic wave and is not directly associated with cycles or frequency. Amplitude refers to the strength or power of a signal but does not indicate how frequently that signal oscillates over time. Thus, Hertz specifically aligns with measuring frequency, making it the correct choice.