By antenna radiated into surrounding environment

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Unformatted text preview: nna is often used for both purposes Radiation Pattern Radiation power radiated in all directions not same performance in all directions as seen in a radiation pattern diagram as radiation an isotropic antenna is a (theoretical) point an in space in radiates in all directions equally with a spherical radiation pattern Antenna Gain Antenna measure of directionality of antenna power output in particular direction verses power that produced by an isotropic antenna that measured in decibels (dB) results in loss in power in another direction effective area relates to size and shape related to gain Terrestrial Microwave Terrestrial used for long haul telecommunications and short point-to-point links requires fewer repeaters but line of sight use a parabolic dish to focus a narrow beam use onto a receiver antenna onto 1-40GHz frequencies higher frequencies give higher data rates main source of loss is attenuation distance, rainfall also interference Satellite Microwave Satellite satellite is relay station receives on one frequency, amplifies or repeats receives signal and transmits on another frequency signal typically requires geo-stationary orbit e.g. uplink 5.925-6.425 GHz & downlink 3.7-4.2 GHz height of 35,784km spaced at least 3-4° apart typical uses television long dista...
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