Tuesday, March 19, 2019
Radio Waves :: essays research papers
Radio Waves     In the modern society, wireless is the most widely employ spiritualist of send and electronic communication it plays a major role in many arassuch as unexclusive safety, industrial manufacturing, processing, agriculture,transportation, entertainment, national defense, space actuate, overseascommunication, news reporting and support forecasting. In radio broadcasts, theyuse the radio strays which can be both(prenominal) microwaves and longer radio waves. Theseare transmitted 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 number of times they pass through a complete cycle persecond or by their wavelength, which is determined by the distance (by meters)that is traveled from the crest of hotshot wave to the crest of the next.     Radio frequencies are measured in units called kilocycle, megahertz, andgigahertz. (1 kilohertz = 1000 hertz 1 megahertz = 106 hertz, 1 gigahertz =109 hertz). solely 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 divided into two groups or bands such as truly low frequency (VLF 10-30 kHz ), low frequency (LF 30-300 KHz), medium frequency ( MF 300-3000KHz), laid-back frequency ( HF 3-30 MHZ) and very high frequency ( very high frequency 30-300MHZ).     Amplitude modulation is the oldest method of transmitting vocalisation andmusic through the airwaves is by amplitude modulation. This is accomplished by cartel 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(prenominal) 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(prenominal) room 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.