In Your Own Words

Analog Modulation is when a low frequency such as a 1 Khz tone is transmitted on a higher radio frequency carrier wave. The carrier signal is modulated to follow the modulating signal.

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Digital modulation is more like a conversion from analog signal to digital bit stream or vice versa. The picture below shows a certain type of modulation scheme called Frequency Shift Key (FSK) When the change of frequency occurs so does the representation of bits, 0 or 1.

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Absorption is the most common RF behavior. If the signal does not bounce off an object, move around an object, or pass through an object, then 100 percent absorption has occurred. Most materials will absorb some amount of an RF signal. The picture below shows a signal being absorbed as it passes through a wall

Reflection may happen when a wave hits a smooth object that is larger than the wave itself, depending upon the media, the wave may bounce in another direction. For example like if a child bouncing a ball off a sidewalk and the ball changing direction.

Scattering can most easily be described as multiple reflections. These multiple reflections occur when the electromagnetic signal’s wavelength is larger than pieces of whatever medium the signal is passing through. Chain link fences, tree foliage, and rocky terrain commonly cause this type of scattering. When striking the uneven surface, the main signal dissipates into multiple reflected signals. The picture below shows how when the large beam of light hits small uneven surface the light scatters in multiple directions.

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