CHARACTERISTICS OF MICROWAVE RADIATION
a. Electromagnetic Nature. Microwaves are one part of the waves in the
electromagnetic spectrum. These invisible waves move outward traveling in an up-and-
down movement. These waves travel outward in all directions from the transmitting
antenna. The more powerful the waves, the farther they travel through space.
Figure 2-5. Microwaves.
(1) Like ordinary radio waves, microwaves can be modulated (changed
according to the sound wave).
Microwaves can carry sound waves.
Microwaves (short waves) are transmitted in narrow beams.
For transmission, microwaves need special antennas, usually shaped
like a bowl.
(5) Microwaves cannot be sent on ordinary wires. They must be sent
through special pipes called waveguides.
b. Non-ionizing. Microwave radiation does not cause ionization. That is,
microwaves do not cause atoms to separate or change into ions.
c. Reflection, Transmission, or Absorption. Microwave radiation travels in
straight lines and is reflected, transmitted, or absorbed. When microwave energy
strikes a surface, it can be reflected back from that surface in the same way that a
mirror reflects back light which hits the mirror. How well the surface reflects back
microwaves depends on the efficiency of the surface as a reflector. Large, smooth,
reflect nearly all of the energy carried by microwaves. The earth's surface is a fairly
as reflective as a mirror, is also a fairly good reflector of microwave radiation.