Radio Waves :: essays research papers

Radio Waves     In the modern society, communicate is the most widely use medium ofbroadcasting and electronic communication it plays a major role in some areassuch as public safety, industrial manufacturing, processing, agriculture,transportation, entertainment, national defense, blank space travel, overseascommunication, news reporting and weather forecasting. In radio receiver broadcasts, theyuse the radio ripples which can be both microwaves and longer radio waves. Theseare transmittable in two ways amplitude modulation (AM ) and frequency modulation( FM ). These two kinds of wave have many differences.     Radio waves are among the many types of electromagnetic waves thattravel within the electromagnetic spectrum. Radio waves can be defined by theirfrequency (in hertz, after Heinich Hertz , who first produced radio waveselectronically), which is matter of times they pass through a complete cycle persecond or by their wavelength, w hich is determined by the distance (by meters)that is traveled from the crest of oneness wave to the crest of the next.     Radio frequencies are measured in units called kilohertz, megahertz, andgigahertz. (1 kilohertz = 1000 hertz 1 megahertz = 106 hertz, 1 gigahertz =109 hertz). All radio waves fall within a frequency range of 3 kilohertz, or3000 cycles per second to 30 gigahertz. Within the range of frequencies, radiowaves are further dual-lane into two groups or phones such as very low frequency (VLF 10-30 kHz ), low frequency (LF 30-300 KHz), medium frequency ( MF 300-3000KHz), elevated frequency ( HF 3-30 MHZ) and very high frequency ( VHF 30-300MHZ).     Amplitude modulation is the oldest method of transmitting voice andmusic through the airwaves is by amplitude modulation. This is accomplished bycombining a sound wave from a microphone, tape, record, or CD with a "carrier"radio wave. The result a wave that transmits voice or programming as itsamplitude ( intensity ) increases and decreases. Amplitude modulation is used bystation broadcasting in the AM band and by most international short wavestations.     Frequency modulation is another way to convey information, voice , andmusic on a radio wave is to slightly change, or modulate, the frequency. Themain advantage of FM broadcasting is of it is static free. But the drawback toFM is since the frequency is varied, station takes up more style on the band.Frequency modulation is, of course, used on the FM band. And it is used for"action band" and ham transmission in the VHF/UHF frequency range.     In amplitude modulation, what is modified is the amplitude of a carrierwave on one specific frequency.