What is adjusted in electronic scanning to change the characteristics of radiated energy?

The adjustment of frequency or phase in electronic scanning is crucial because it significantly influences the characteristics of radiated energy. When the frequency is altered, it directly affects the wavelength of the electromagnetic energy being emitted. A higher frequency corresponds to a shorter wavelength, while a lower frequency results in a longer wavelength. This relationship is essential in determining how well the radiated energy propagates and interacts with various media or objects.

Additionally, adjusting the phase of the emitted energy allows for the control of how waves from multiple antennas interact, enabling the directionality and beam shape of the radiated energy to be modified. This is especially important in applications like radar and communications, where precise control over the direction and focus of the signal can enhance detection capabilities and improve signal quality.

In contrast, although other options touch on aspects of radiated energy, they do not directly relate to the fundamental characteristics like frequency and phase that primarily influence how energy is radiated and its propagation through space. Thus, the choice of frequency or phase is the most relevant to the question regarding adjustments that change the characteristics of radiated energy.