Flashcards
CWNA - Flash Cards - Chapter 4
Cards in this deck (28)
- 1Azimuth chartH-plane = top-down view
- 2Elevation chartE-plane = side view
- 3Represents a change of 5 dBEach concentric circle on a logarithmic chart
- 4Measurement from the centre, or strongest point, of the antenna signal to each of the points along the horizontal and vertical axes where the signal decreases by half powerBeamwidth
- 5Radiate in all directionsOmnidirectional Antennas
- 6Patch, Panel, Yagi are ______ types of antennaSemi directional Antennas
- 7Can be used effectively in libraries, warehouses, and retail stores with long aisles of shelvesPatch
- 8Have a horizontal beamwidth of 180 degrees or less, a minimal amount of signal will radiate outside of the buildingPatch
- 9Used for short to medium distance point to point connections of up to about 3.2kmsYagi
- 10Strictly for point to point communications (typically between buildings)Highly Directional Antennas
- 11Types of Highly directional antennas:- Parabolic Dish
- Grid Antennas - 12Special type of high-gain, semi-directional antenna that provides a pie-shaped coverage patternSector Antennas
- 13A group of two or more antennas that are integrated together to provide coverageAntenna Arrays
- 14Method of concentrating RF energyBeamforming
- 15Beamforming using directional antennas to provide a fixed radiation patternStatic Beamforming
- 16Focuses RF energy in a direction in a particular shapeDynamic Beamforming
- 17Uses an adaptive antenna array that manoeuvres the beam in the direction of the receiver dynamicallyDynamic Beamforming
- 18Transmits multiple phase-shifted signals with the hope and intention that they will arrive in-phase at the location where the transmitter believes that the receiver is locatedTransmit Beamforming
- 19Use _________ channel-sounding process to optimize the phase differentials between the transmit chainsImplicit TxBF
- 20Requires feedback from the stations in order to determine the amount of phase-shift required for each signalExplicit TxBF
- 21Defined in 802.11ac equiring the use of channel measurement frames and both the transmitter and receiver to support beamformingExplicit TxBF
- 22When light travels from one point to another it travels across what is perceived to be an unobstructed straight line which is known as ____________________Visual Line of Sight (Visual LOS)
- 23Has no bearing on whether or not a RF transition will be successful or notVisual Line of Sight (Visual LOS)
- 24RF Line of Sight is also referred to as ________The Fresnel zone
- 25Imaginary, elongated, football-shaped area that surrounds the path of the visual LOS between two point-to-point antennas.The Fresnel zone
- 26If the _______ Fresnel Zone becomes obstructed it will have a negative influence on the RF CommunicationsFirst Fresnel zone
- 27Two or more antennas with a receiver functioning together to minimize the negative effects of multipath.Antenna diversity
- 28Measurement of the change in impedance to the AC SignalVoltage Standing Wave Ratio
(VSWR)
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- CWNA Flashcards on CWNA - Flash Cards - Chapter 4, created by Amit Pindoria on 21/02/2017.
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