1. جامعة النجاح الوطنية كلية العلوم قسم الفيزياء / فرعي إلكترونيات Presented by : Anhar Hamadneh TO : Dr. Issam Al Ashqar 2013

2. M ICROWAVE MICROWAVE IN,,, COMMUNICATION SYSTEMS. RADAR SYSTEMS. MICROWAVE OVENS (IF IS FREE TIME).

3. M ICROWAVES D EFINITION  Microwaves; are electromagnetic waves with I. wavelengths ranging from as long as one meter 1m to as short as one millimeter 1 mm, or equivalently. II. frequencies between 300 MHz (0.3 GHz) and 300 GHz. This definition includes both UHF and EHF (millimeter waves),. In all cases, microwave includes the SHF band (3 to 30 GHz, or 10 to 1 cm) at minimum, See fig,, 1fig,, 1

4. Electromagnetic Spectrum Source from Hyper Physics

5. M ICROWAVES USED FOR LOTS OF THINGS …. Microwaves communications. Ex - cell phones. radar. microwave ovens. astronomy. Heating. TO see full text about microwave heating click TO see full text about microwave heating click TO see full text about microwave heating click

6. VIRipnpr.jpl.nasa.gov

7. Microwave is EM wave. EM wave is transverse wave. See fig ’a’ Fig ‘a’

8. It is made up of magnetic and electric fields that are at right angles to each other and at right angles to the direction of propagation. It travels in a straight line at approximately the speed of light. See fig below

9. M ICROWAVE TRANSMISSION Microwave dishes are commonly used to transmit data over long distances. A dish-to-dish microwave setup could easily cover 4 miles. It relies on high frequency microwave radiation that travels at the speed of light. Microwaves get weaker as they get further away from their source, they also need to be line-of-sight so a large building in the way would tend to block the signal. The microwave dishes would need to be installed by a professional contractor which would add to the already high cost of equipment.

10.  Advantages : Can cover large distances over rough terrain where you could'nt bury cables. High speeds. wide bandwidth multichannel transmissions  Disadvantages : Equipment very expensive. Relies on line-of-sight. Can be prone to interference such as passing airplanes and rain.

12. G ROUND MICROWAVES { T ERRESTRIAL } transmission systems consisting of at least two radio transmitter/receivers., connected to high gain antennas (directional antennas which concentrate in electromagnetic field) focused in pairs on each other. The operation is point-to-point-communications are established between two antennas with line- of-sight visibility.point-to-point- This can be contrasted to point-to- multipoint systems like broadcast radio or television.

13. POINT – TO – POINT LINKS

14. H OW T ERRESTRIAL ( GROUND ) M ICROWAVE T RANSFER AND R ECEIVE D ATA Terrestrial( GROUND ) microwave communication employs Earth-based transmitters and receivers to transfer and receive data. The frequencies used are in the low- gigahertz range, which limits all communications to line-of-sight. Example of terrestrial {ground} microwave equipment -telephone relay towers, which are placed every few miles to relay telephone signals cross country.

15. An Antenna is : An An effective interface between the radio and free space: Radio Antenna Free space a For Terrestrial Communications, antennas must be directional: Radio http//www.ftsm.ukm.my

16. G a (dBi) = 10 log 10  [ 4  A a /    Where: G a = Antenna Directive Gain (Catalog spec)  = Aperture Efficiency (50-55%) A a = Antenna Aperture Area  = Wavelength (speed of light / frequency) F ORMULA P ARABOLIC A NTENNA D IRECTIVE G AIN

17. A DVANTAGES OF T ERRESTRIAL ( GROUND ) M ICROWAVE OVER S ATELLITE Lower cost Reduced latency Reduced Size & Weight

18. S ATELLITE MICROWAVES Space station that receives microwave signals from earth-based station, amplifies signals and broadcasts signals back to a number of earth- based stations.. Transmitted waves can be received on the all ground through a satellite antenna...

19. S ATELLITE M ICROWAVE T RANSMISSION a microwave relay station in space can relay signals over long distances geostationary satellites remain above the equator at a height of 22,300 miles ( geosynchronous orbit) travel around the earth in exactly the time the earth takes to rotate

20. dish uplink station downlink station satellite Transponder in speac 22,300 miles S ATELLITE T RANSMISSION P ROCESS

21. S ATELLITE C OMMUNICATIONS A special form of microwave communications in a geosynchronous orbit Signals sent from the ground to a satellite; Then relayed to its destination ground station Long propagation delay –Due to great distance between ground station and satellite (Even with signals traveling at light speed) www.utdallas.edu

22. Relies on line-of-sight.

23. Branch Offices Corporate Offices Gas Stations Apartment Buildings Residential Emergency Response

24. Microwaves Satellite FORMS

28. C ELL P HONE F REQUENCY R ANGE : 850 AND 1900 MH Z

29. Radar_ antenna

30. R ADAR D EFINITION Radar is a system that uses electromagnetic waves to identify the range, altitude, direction, or speed of both moving and fixed objects such as aircraft, ships, motor vehicles, weather formations.

31. R ADAR USING  Radar is used in many contexts; 1. including meteorological detection of precipitation. 2. measuring ocean surface waves. 3. air traffic control. 4. police detection of speeding traffic. 5. by the military.

32. R ADAR P RINCIPLES

33. http://www.sciencelearn.org.nz

34. MICROWAVE OVENS P RINCIPLES microwave oven works by passing non-ionizing microwave radiation, usually at a frequency of 2.45 gigahertz (GHz)—a wavelength of 122 millimetres (4.80 in)—through the food. Microwave radiation is between common radio and infrared frequencies. Water, fat, and other substances in the food absorb energy from the microwaves in a process called dielectric heating

35. MICROWAVE OVENS … WORKS o Water is a polar molecule mean a positive charge at one end and a negative charge at the other,. result,, This means it will try to orient itself a particular way in alternating electric field of the microwaves..,,, This molecular movement represents heat. +  + H 2 o molecule

36. M ICROWAVE O VEN WORKS.. CONT oscillating electric field time Water oscillating with time in electric field = heat

38. D IFFERENCE BETWEEN C ELL P HONE AND M ICROWAVE O VEN Power Power Cell Phone 0.1 Watts Cell Phone 0.1 Watts Microwave ovens 1000 Watts Microwave ovens 1000 Watts Modulation Modulation Cell phone is carrying info Cell phone is carrying info Microwave is not Microwave is not

39. THANKS !!