Why is a satellite dish necessary to receive satellite broadcasts?
Normal television broadcasts use electromagnetic waves with relatively low frequencies and long wavelengths while satellite broadcasts use waves with relatively high frequencies and short wavelengths. The short wavelength waves from a satellite are known as microwaves while the longer wavelength waves from a normal broadcast station are generally known as radio waves. Since the optimal antenna size for receiving a particular electromagnetic wave is proportional to the wavelength of the wave, you need a smaller antenna to receive the microwaves from a satellite than you do the radio waves from a normal television station. However, the microwaves from a satellite are much weaker than the radio waves from a nearby television station and a small microwave antenna isn’t likely to absorb enough of them to produce a useable signal. The solution to this dilemma is to concentrate the microwaves from a satellite with the help of an optical imaging system. Although it may not look like one, a sat
