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MICROWAVE :- These  are a form of electromagnetic radiation with wavelengths ranging from as long as one meter to as short as one millimeter, which is equal to the frequencies between 300 MHz (0.3 GHz) and 300 GHz. This definition includes both UHF and EHF both are millimeter waves, and various sources use different boundaries. In every case, microwave includes the entire SHF band (3 to 30 GHz, or 10 to 1 cm) at minimum, with RF engineering often putting the lower boundary at 1 GHz (30 cm), and the upper around 100 GHz (3 mm).The prefix "micro-" in "microwave" is not meant to suggest a wavelength in the micrometer range. It indicates that microwaves are "small" compared to waves used in typical radio broadcasting, in that they have shorter wavelengths. The boundaries between far infrared light, terahertz radiation, microwaves, and ultra-high-frequency radio waves are arbitrary and are used variously between different fields of study.                     

INFRARED (IR) :- This  light is electromagnetic radiations with longer wavelengths than those of visible light, extending from the nominal red edge of the visible spectrum at 700 nanometer (nm) to 1 mm. Wavelengths of these ra ys corresponds to a frequency range of approximately 430 THZ down to 300 GHz, and includes most of the thermal radiation emitted by objects near room temperature. Infrared light is emitted or absorbed by molecules when they change their rational-vibrations movements. It was first discovered in 1800 by astronomer William Herschel. Slightly more than half of the energy from the Sun arrives on Earth in the form of infrared radiation. The balance between absorbed and emitted infrared radiation has a critical effect on Earth's climate. History of Infrared:- The discovery of this radiation is ascribed to William Herschel, the astronomer, in the early 19th century. He published his results in 1800 before the Royal Society of London. He used a prism to refract li

WIRELESS COMMUNICATION Introduction:- Wireless communication  is the communication between two or more points that are not connected by an electrical conductor. It permits services, such as long-range communications, that are impossible or impractical to implement with the use of wires The common wireless technologies use electromagnetic wireless telecommunications, such as radio. With radio waves distances can be short, such as a few meters for television or as far as thousands or even millions of kilometers for deep-space radio communications. It encompasses various types of fixed, mobile, and portable applications, including  cellular telephones ,personal digital assistants (PDAs), and wireless networking . Other examples include GPS units, garage door openers, wireless computer mice, keyboards and headsets, headphones, radio receivers, satellite television, broadcast television and cordless telephones .Less common methods of achieving wireless communications include the us