SUBJECT: ANTENNAS AND WAVE PROPAGATION 1. Define an antenna. Antenna is a transition device or a transducer between a guided wave and a free space wave or vice versa. Antenna is also said to be an impedance transforming device. 2. What is meant by radiation pattern? Radiation pattern is the relative distribution of radiated power as a function of distance in space .It is a graph which shows the variation in actual field strength of the EM wave at all points which are at equal distance from the
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US ARMY SIGNAL CENTER AND FORT GORDON PRINCIPLES OF RADIO WAVE PROPAGATION (SC:25C) EDITION DATE: FEBRUARY 2005 PRINCIPLES OF RADIO WAVE PROPAGATION Subcourse Number SS0130 EDITION B United States Army Signal Center and Fort Gordon Fort Gordon‚ Georgia 30905-5000 10 Credit Hours Edition Date: February 2005 SUBCOURSE OVERVIEW This subcourse is designed to teach the principles of radio wave propagation. The prerequisite for this subcourse is that you
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spreads across a medium (i.e.‚ air or water) as a mechanical longitudinal wave formed by pressure. A Mechanical longitudinal wave can also be called compression wave as it generates compressions and rarefaction when traveling through a medium. (Sound Is a Pressure Wave - Physics Classroom) The amplitude of a sound wave is the difference between the pressure of the undisturbed air and the maximum pressure caused by the wave. The Speed of sound deviates with the temperature‚ and density of the medium
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Korean Wave Hanryu‚ the Korean wave refers to the significant increase in the popularity of South Korean entertainment‚ trends and culture beginning in the 1990s‚ especially in countries of Asia‚ and more recently in other parts of the world. It presents a prodigious surge in the international visibility of Korean culture. The terminology was coined in mid-1999 by Beijing journalists‚ appalled by the fast growing popularity of Korean wave in China. The wave is more than a mere cultural phenomenon;
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Stoneley-wave attenuation and velocity are sensitive to fracture and formation permeability‚ especially at low frequencies. Stoneley-wave velocity declines‚ and its attenuation increments‚ as permeability increments. Beginning endeavors (started in the 1970s) to get permeability information from Stoneley information was unsuccessful because neither the significant low-frequency instruments nor the proper handling techniques had been created. The parallel advancement of present day multi-pole array
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Constructive waves deposit eroded material along the shore‚ which eventually builds up over time to form a beach. This occurs when the swash is stronger than the backwash‚ depositing more sediment than it transports elsewhere. Although beaches are a landform of deposition‚ they can also be considered to be a landform of erosion. When waves are huge and high‚ the backwash is more powerful than the swash‚ removing more loose material than it deposits. These types of waves are known as destructive waves. The
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motion‚ even when it is really cold. Gas Waves 10. Waves transfer _energy_ from place to place‚ and it spreads _out evenly_ from the source. 11. What is a mechanical wave? _A wave that requires a medium to travel through._ Example of a mechanical wave? _Sound_ An example of a non-mechanical wave (electromagnetic)? _Light_ 12. Label the following parts on a longitudinal wave: Compression a. Compression b. Rarefaction 13. In a longitudinal wave‚ the particles move Rarefaction parallel / perpendicular
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History 2112 Second-Wave Feminism Towards the end of the twentieth century‚ feminist women in America faced an underlying conflict to find their purpose and true meaning in life. “Is this all?” was often a question whose answer was sought after by numerous women reaching deeper into their minds and souls to find what was missing from their life. The ideal second-wave feminist was defined as a women who puts all of her time into cleaning her home‚ loving her husband‚ and caring for her children
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The art of wave riding (‘he’enalu’‚ in old Hawaiian) was practiced in many coastal locations around the tropics among Pacific Islanders. "He’e" means to go from a solid to a liquid and "nalu" means surfing motion of a wave. This stand-up pastime of surfing came to its climax in Hawaii not only because of its coast having warm water and constant waves but Hawaiians are innately ocean people. Traditionally surfing prowess gained you social rank and power politically in the village. Commoners could
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5AR4 Full Wave Rectifier The 5AR4 is a heater-cathode twin diode designed for full-wave rectifier opertion. High output current and small size make this tube especially suitable for compact amplifier designs. ELECTRICAL Cathode .................................................................................................................. coated unipotential Heater Voltage AC or DC ....................................................................................... 5.0 ! 10% Volts Heater
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