7787601
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 |
| Azimuth chart | H-plane = top-down view |
| Elevation chart | E-plane = side view |
| Represents a change of 5 dB | Each concentric circle on a logarithmic chart |
| Measurement 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 power | Beamwidth |
| Radiate in all directions | Omnidirectional Antennas |
| Patch, Panel, Yagi are ______ types of antenna | Semi directional Antennas |
| Can be used effectively in libraries, warehouses, and retail stores with long aisles of shelves | Patch |
| Have a horizontal beamwidth of 180 degrees or less, a minimal amount of signal will radiate outside of the building | Patch |
| Used for short to medium distance point to point connections of up to about 3.2kms | Yagi |
| Strictly for point to point communications (typically between buildings) | Highly Directional Antennas |
| Types of Highly directional antennas: | - Parabolic Dish - Grid Antennas |
| Special type of high-gain, semi-directional antenna that provides a pie-shaped coverage pattern | Sector Antennas |
| A group of two or more antennas that are integrated together to provide coverage | Antenna Arrays |
| Method of concentrating RF energy | Beamforming |
| Beamforming using directional antennas to provide a fixed radiation pattern | Static Beamforming |
| Focuses RF energy in a direction in a particular shape | Dynamic Beamforming |
| Uses an adaptive antenna array that manoeuvres the beam in the direction of the receiver dynamically | Dynamic Beamforming |
| Transmits 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 located | Transmit Beamforming |
| Use _________ channel-sounding process to optimize the phase differentials between the transmit chains | Implicit TxBF |
| Requires feedback from the stations in order to determine the amount of phase-shift required for each signal | Explicit TxBF |
| Defined in 802.11ac equiring the use of channel measurement frames and both the transmitter and receiver to support beamforming | Explicit TxBF |
| When 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) |
| Has no bearing on whether or not a RF transition will be successful or not | Visual Line of Sight (Visual LOS) |
| RF Line of Sight is also referred to as ________ | The Fresnel zone |
| Imaginary, elongated, football-shaped area that surrounds the path of the visual LOS between two point-to-point antennas. | The Fresnel zone |
| If the _______ Fresnel Zone becomes obstructed it will have a negative influence on the RF Communications | First Fresnel zone |
| Two or more antennas with a receiver functioning together to minimize the negative effects of multipath. | Antenna diversity |
| Measurement of the change in impedance to the AC Signal | Voltage Standing Wave Ratio (VSWR) |
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