Caffeine Information. Caffeine is naturally found in cocoa beans, coffee beans and tea and is synthetically produced for use in certain medications and in beverages. This substance is a stimulant drug that quickly enters the bloodstream and affects the brain.
Frequency Range Chart. The radio spectrum refers to the section of the electromagnetic spectrum that holds all possible radio frequencies ranging from 3 kHz to 300 GHz.Radio frequency is used for radio communication technology, wireless networks and telecommunication systems.he radio spectrum refers to the section of the electromagnetic spectrum that holds all possible radio frequencies ranging from 3 kHz to 300 GHz. Radio frequency is used for radio communication technology, wireless networks and telecommunication systems.
The Radio Frequency Spectrum In the radio frequency spectrum (Figure 1-2), the usable frequency range forradio waves extends from about 20 kHz (just above sound waves) to above30,000 MHz. A wavelength at 20 kHz is 15 kilometers long. At 30,000 MHz,the wavelength is only 1 centimeter.