7787471
Description
Flashcards by Amit Pindoria, updated more than 1 year ago
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Created by Amit Pindoria
about 7 years ago
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| Question | Answer |
| The distance between the two successive crescents (peaks) or two successive throughs (valleys) | A wavelength |
| how often an RF signal cycles in a certain time period | Frequency |
| Frequency of 1,000,000,000 (billion) cycles per second | 1Ghz |
| The height of the wave | Amplitude |
| Most common RF behaviour | Absorption |
| Wave hits smooth object that is larger than the wave itself, dependant on the material the signal may bounce in another direction | Reflection |
| Multiple reflections | Scattering |
| Signal passes through a medium with different density causing the wave to change direction. | Refraction |
| Causes of refraction | - Water Vapour - Changes in air temperature - Changes in air pressure |
| Signal is bent around an object | Diffraction |
| Decrease in amplitude | Loss (Attenuation) |
| Loss of signal strength caused by the natural broadening of the waves | Free Space Path Loss (FSPL) |
| Occurs when 2 or more signals arrive at the receiving station at the same time or within nanoseconds of each other | Multipath |
| Multiple RF signal paths arrive at the same time and are in phase (phase differences of 0 to 120 degrees) will result in increased signal strength | Upfade |
| Multiple RF signals arrive at the same time but are out of phase (phase difference of 121 to 179 degrees) Results in decrease signal strength | Downfade |
| Multiple RF signals arrive at the same time and are 180 degrees out of phase of each other | Nulling |
| Multiple signals arriving but not at the same time the receiver might have trouble demodulating the signal. | Data Corruption |
| Increase to signal on the transmitter or transceivers side through the use of an amplifier. | Active Gain |
| Focusing the antenna, the inner workings of the antenna make the signal stronger. | Passive Gain |
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