CWT CWT Antenna Systems & Site Surveys 1 — Questions and Answers
Question 1: What is the primary purpose of conducting a wireless site survey before deploying a WLAN?
- To identify RF coverage, interference, and optimal AP placement (Correct answer)
- To purchase the correct number of access points
- To configure SSID names before installation
- To register the network with the FCC
Correct answer: To identify RF coverage, interference, and optimal AP placement
A site survey identifies RF coverage gaps, interference sources, and optimal access point placement to ensure reliable wireless connectivity.
Question 2: Which antenna type radiates power equally in all horizontal directions, making it ideal for open-area deployments?
- Yagi directional antenna
- Parabolic dish antenna
- Omnidirectional antenna (Correct answer)
- Sector antenna
Correct answer: Omnidirectional antenna
An omnidirectional antenna radiates RF energy uniformly in a 360-degree horizontal pattern, making it suitable for central placement in open environments.
Question 3: What unit is used to measure antenna gain relative to an isotropic radiator?
- dBm
- dBi (Correct answer)
- dBd
- MHz
Correct answer: dBi
dBi (decibels relative to isotropic) measures antenna gain compared to a theoretical isotropic radiator that radiates equally in all directions.
Question 4: What does VSWR (Voltage Standing Wave Ratio) indicate in an antenna system?
- The frequency range of the antenna
- The amount of RF power reflected due to impedance mismatch (Correct answer)
- The polarization of the antenna
- The antenna's operating temperature range
Correct answer: The amount of RF power reflected due to impedance mismatch
VSWR measures the ratio of reflected to forward power caused by impedance mismatch between the antenna and transmission line, with 1:1 being ideal.
Question 5: Which passive site survey method involves walking a facility with a device to record signal strength without any traffic generation?
- Active survey
- Predictive survey
- Passive survey (Correct answer)
- Spectrum analysis
Correct answer: Passive survey
A passive survey captures real-world RF signal levels by listening for existing Wi-Fi beacons without generating test traffic.
Question 6: What is antenna polarization and why does it matter for wireless links?
- The color coding of antenna cables
- The orientation of the electric field emitted by the antenna, which must match on both ends (Correct answer)
- The number of frequencies an antenna supports
- The mounting angle of the antenna on a pole
Correct answer: The orientation of the electric field emitted by the antenna, which must match on both ends
Antenna polarization describes the orientation of the electric field; mismatched polarization between transmitter and receiver causes significant signal loss.
CWT CWT Antenna Systems & Site Surveys 1
What is the primary purpose of conducting a wireless site survey before deploying a WLAN?