Microwave and Infrared Lesson PDF

The microwave region in the EM spectrum lies somewhere from 300 MHz to 300 GHz, with wavelength corresponding to 10-3 m to 10-1m. They fall between infrared radiation and radio waves in the electromagnetic spectrum  James Clerk Maxwell is...

The microwave region in the EM spectrum lies somewhere from 300 MHz to 300 GHz, with wavelength corresponding to 10-3 m to 10-1m. They fall between infrared radiation and radio waves in the electromagnetic spectrum  James Clerk Maxwell is credited for discovering microwaves in 1864. https://images.app.goo.gl/C1Ys3df4CJcYrLdU7  1. Metal surfaces microwaves. Microwaves with a certain wavelength pass through the earth’s atmosphere and can be useful in transmitting information to and from satellites in orbit. Hence, the satellite dishes are made of metal as they reflect https://images.app.goo.gl/yYuy4N1q9mdXhFz79 microwaves well.  2. Microwaves of certain frequencies are by water. This property of microwaves is useful n cooking. Water in the food absorbs microwaves, which causes the water to heat up, https://images.app.goo.gl/j4Td1yysjG5LmAzA8 therefore cooking the food. 3. Microwave transmission is by wave effects such as refraction, reflection, interference, and diffraction.  4. Microwaves can glass and plastic. This is the reason why we use a plastic or glass container in a microwave oven and not metal containers, as metal reflects microwaves. https://images.app.goo.gl/nZaMjQ9J7GTH6CVb7  They are considered as and are mainly used for , especially from 2 GHz to 40 GHz. They were mostly used for before the introduction of optical fibers. Used to send signals for as well as video or audio https://images.app.goo.gl/hZ6TJ6Jym89DrmT97 feeds from production vans to broadcast stations.  Used as for disaster management and mapping https://images.app.goo.gl/dYdVqKsyDQhvyewc8 are used for weather forecasting. https://images.app.goo.gl/KeskA8HCgEaUqDbD8 It is a common kitchen appliance. It uses microwaves to cook food by in the food. In addition to heating leftover food, a microwave is used in industrial processes for drying and curing products.  Microwaves are highly used in the medical field. uses the heat of the microwaves to shrink or destroy tumors. https://images.app.goo.gl/AbLAn3VfsdfjyfX37 is used to monitor the progress of treatment in breast cancer, which can be distinguished as benign or malignant through microwave tomography. https://images.app.goo.gl/r8SGjKKVKeg5txvh9  Infrared literally means “ ”. They have very low frequency than the red part of the visible light. Frequency 3x1011 Hz to 4 x 1014 Hz and its wavelength ranging https://images.app.goo.gl/dZRBBaZ6VpRGN7dp9 from 7.5 x 10-7 m to 10-3.  ,a British astronomer, discovered infrared in 1800. https://images.app.goo.gl/GhEFwC9Cq6QTqiFu5  Infrared rays are used in remote controls for television sets, burglar alarm systems, night vision cameras, and certain types of thermometers. https://images.app.goo.gl/MSFLfEED9dKGJUjSA  Food can also be using infrared radiation. https://images.app.goo.gl/tz5LYJifxL2mG1eg7 (left) Infrared photographs taken from a satellite with special films provide useful details of the vegetation on the Earth’s surface. (right) Infrared scanners are used to show the temperature variation of the body. This can be used for medical diagnosis. (left) Infrared remote controls are used in TVs, video cassette recorders, and other electronic appliances. (right) Infrared telescopes are used for seeing in the dark.  Autofocus camera has a transmitter that sends out infrared pulses. The pulses are reflected by the object to be photographed back to the camera. The distance of the object is calculated by the time lag between the sending and receiving of pulses. https://images.app.goo.gl/fpZ291hKKiiAg3CPA The lens is then driven by a built-in motor to adjust to get the correct focus of the object 1. Augmentative communication device 2. Car locking systems 3. Computers (mouse, keyboards, printers) 4. Emergency response systems 5. Headphones 6. Home security systems 7. Navigation systems 8. Signages 9. Telephones 10. Some toys  1. Low power requirements that makes it ideal for laptops, and other technological devices 2. Low circuitry costs 3. Simple circuitry: can be incorporated in the integrated circuit of a product 4. Higher security than radio waves since it requires “line of sight” transmission 5. Portable 6. Not likely to interfere to signals https://images.app.goo.gl/dZRBBaZ6VpRGN7dp9 from other device  1. Transmitters and receivers should be directly aligned to connect and communicate 2. Can be blocked by common materials 3. Distance sensitive; performance drops as distance increases 4. Weather sensitive; transmission can easily be affected by weather conditions like rains 5. Can also be affected by light such as sunlight https://images.app.goo.gl/dZRBBaZ6VpRGN7dp9