the transmissions are focused with a desired area. When the area is focused‚ then the emissions don‟t go outside that designated area and thus minimizing the interference to the other systems. This leads more efficient spectrum usage. Satellite‟s antenna patterns play an important role and must be designed to best cover the designated geographical area (which is generally irregular in shape). Satellites should be designed by keeping in mind its usability for short and long term effects throughout
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MOBILE COMPUTING Chapter 1: Outline 1.1 Introduction to Mobile Computing 1.2 Radio Propagation 1.3 Antennas 1.4 Cellular Systems 1.5 Wireless Link Characteristics ERIC SAVIOUR ARYEE OKAI OCT‚2013 MOBILE COMPUTING 1.1 INTRODUCTION What is Mobile Computing? Mobile Computing is a technology that allows transmission of data‚ voice and video via a computer or any other wireless enabled device without having to be connected to a fixed physical link. ERIC SAVIOUR ARYEE OKAI OCT
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A parabolic antenna for Erdfunkstelle Raisting‚ based in Raisting‚ Bavaria‚ Germany. To direct microwaves in narrow beams for point-to-point communication links or radiolocation (radar)‚ a parabolic antenna is usually used. This is an antenna that uses a parabolic reflector to direct the microwaves. To achieve narrow beamwidths‚ the reflector must be much larger than the wavelength of the radio waves. The relatively short wavelength of microwaves allows reasonably sized dishes to exhibit the desired
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Wiley‚ 2010. [21] P [22] P. V. Nikitin‚ K. V. S. Rao‚ and S. Lazar‚ “An overview of near field UHF RFID”‚ IEEE RFID conference‚ 2007‚ pp. 167-174 [23] A section”‚ IEEE Antennas and Propagation Society International Symposium‚ Jul. 1997‚ vol. 2‚ pp. 1172 - 1175 [26] L [29] X. Qing‚ C. K. Goh‚ Z. N. Chen‚ “Segmented loop antenna for UHF near-field RFID applications”‚ Electronics Letters‚ vol. 45 ‚ no. 17‚ 2009 [30] L [31] Y. Tanaka et al.‚ ” Change of read range for UHF passive RFID tags in close
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CHAPTER 4 TRANSMISSION MEDIA 4.1 Guided Transmission Media Twisted Pair Coaxial Cable Optical Fiber 4.2 Wireless Transmission Antennas Terrestrial Microwave Satellite Microwave Broadcast Radio Infrared 4.3 Wireless Propagation Ground Wave Propagation Sky Wave Propagation Line-of-Sight Propagation 4.4 Line-of-Sight Transmission Free Space Loss Atmospheric Absorption Multipath Refraction 4.5 4.6 Recommended Reading and Web Sites Key Terms‚ Review Questions‚ and Problems Key Terms Review Questions
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Wirelessly Charging Mobile Devices from Ambient RF Sources ABSTRACT: Wireless charging is any of several methods of charging batteries without the use of cables or device-specific AC adaptors. Wireless charging can be used for a wide variety of devices including cell phones‚ laptop computers and MP3 players as well as larger objects‚ such as robots and electric cars. Radio charging is used for charging items with small batteries and low power requirements‚ such as watches‚ hearing aids‚ medical
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minimum transmitter power shall be 10 kW. The antenna height is limited to 2‚000 ft. above the average terrain. Class-A stations shall only be allowed in Metro Manila Classand Metro Cebu. Cebu. 1 Classes of FM Broadcast Stations Class-B Stations ClassA Class-B station shall have an authorized transmitter Classpower not exceeding 10 kW and an effective radiated power (ERP) not exceeding 30 kW. The minimum transmitter power shall be 1 kW. The antenna height is limited to 500 ft. above the average
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reaching the receiving antenna multiple times via different angles and at slightly different times. In radio‚ multiple-input and multiple-output‚ or MIMO (commonly pronounced my-moh or me-moh)‚ is the use of multiple antennas at both the transmitter and receiver to improve communication performance. It is one of several forms of smart antenna technology. Note that the terms input and output refer to the radio channel carrying the signal‚ not to the devices having antennas. MIMO technology has attracted
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TERRESTRIAL MICROWAVE COMMUNICATION SYSTEM DESIGN DESCRIPTION OF THE MICROWAVE BEAM: 1. The microwave beam behaves like a light beam and it tends to follow a straight line and azimuth. 2. The changes on temperature‚ pressure and relative humidity tends to refract the microwave beam. So it will follow on a slightly curved path. The radio horizon exists. 3. It is diffracted when grazing over an obstacle. A small shadow area created when some of the energy is redirected. 4. The beam
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CHAPTER ONE - INTRODUCTION 1.1 PURPOSE OF INDUSTRIAL ATTACHMENT The Industrial Attachment program also known as Student Industrial Work Experience Scheme (SIWES) fulfills part of the requirement in pursuing the degree of Bachelor of Science (Computer Science) in the Redeemer’s University. This is a training that should last for a minimum of six months. It is intended to expose student to the real life working experience. 1.2.1 OBJECTIVES OF SIWES The objectives of SIWES are: *
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