INFRARED(IR)

[attachment=16346]

INTRODUCTION

WHAT IS INFRARED(IR) :
IR is a invisible light which has very low wavelength and a frequency range of 10^16 to 10^17.IR is placed before the visible light in the electromagnetic spectrum on frequency scale.The electromagnetic spectrum classifies electromagnetic energy according to frequency or wavelength (both described below). As shown in Figure 1, the electromagnetic spectrum ranges from energy waves having extremely low frequency (ELF) to energy waves having much higher frequency, such as x-rays.



IR TECHNOLOGY(WIRELESS TECHNOLOGY) :
IR wireless is the use of wireless technology in devices or systems that convey data through infrared (IR) radiation. Infrared is electromagnetic energy at a wavelength or wavelengths somewhat longer than those of red light. The shortest-wavelength IR borders visiblered in the electromagnetic radiation spectrum;the longest-wavelength IR borders radio waves.


MERITS AND DEMERITS OF IR TECHNOLOGY :
Infrared technology offers several important advantages as a form of wireless communication. Advantages and disadvantages of IR are first presented, followed by a comparative listing of radio frequency (RF) advantages and disadvantages.

IR Advantages:
1. Low power requirements: therefore ideal for laptops, telephones, personal digital assistants
2. Low circuitry costs: $2-$5 for the entire coding/decoding circuitry


IR Disadvantages:
1. Line of sight: transmitters and receivers must be almost directly aligned (i.e. able to see each other) to communicate
2. Blocked by common materials: people, walls, plants, etc. can block transmission
3. Short range: performance drops off with longer distances
4. Light, weather sensitive: direct sunlight, rain, fog, dust, pollution can affect transmission
5. Speed: data rate transmission is lower than typical wired transmission