SPIRAL ANTENNA – Study Material

In microwave systems, a spiral antenna is a type of RF antenna. It is shaped as a two-arm spiral, or more arms may be used. Spiral antennas were first described in 1956. Spiral antennas belong to the class of frequency independent antennas which operate over a wide range of frequencies. Polarization, radiation pattern...
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OSCILLATING DIPOLE – Study Material

UHF half–wave dipole Dipole antenna used by the radar altimeter in an airplane A half-wave dipole antenna receiving a radio signal. The incoming radio wave (whose electric field is shown as E, green arrows) causes an oscillating electric current within the antenna elements (black arrows), alternately charging the two sides of the antenna positively (+) and...
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ANTENNA – Study Material

In radio, an antenna is the interface between radio waves propagating through space and electric currents moving in metal conductors, used with a transmitter or receiver. In transmission, a radio transmitter supplies an electric current to the antenna’s terminals, and the antenna radiates the energy from the current as electromagnetic waves (radio waves). In reception, an antenna...
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FILTER – Study Material

In signal processing, a filter is a device or process that removes some unwanted components or features from a signal. Filtering is a class of signal processing, the defining feature of filters being the complete or partial suppression of some aspect of the signal Most often, this means removing some frequencies or...
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ATTENUATOR (ELECTRONICS) – Study Material

  An attenuator is an electronic device that reduces the power of a signal without appreciably distorting its waveform. An attenuator is effectively the opposite of an amplifier, though the two work by different methods. While an amplifier provides gain, an attenuator provides loss, or gain less than 1. onstruction and usage Attenuators are usually passive devices made from simple voltage...
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