For outdoor WLAN coverage, which of the following expressions is correct? (Multiple choice)

Question

Options

• AThe higher the antenna gain, the stronger the directivity of the antenna, and the weaker the
• BThe feeder interface must match the selected antenna
• CThe length of the feeder must not exceed 2 meters
• DOutdoor antennas should not blindly pursue high gain

• A
  82% (36)
• C
  18% (8)

Explanation

A is correct because antenna gain and directivity are directly related - higher gain concentrates signal in a narrower beam (stronger directivity), which inherently reduces coverage in other directions (weaker omnidirectional spread). This is a fundamental antenna trade-off.

B is correct because mismatched feeder interfaces cause signal reflection, power loss, and potential equipment damage - impedance matching (typically 50Ω) between feeder and antenna is a hardware requirement, not a preference.

D is correct because high-gain antennas narrow the beam pattern significantly, which can create coverage dead zones in a real-world outdoor deployment with varied terrain and user locations. Practical coverage needs should drive antenna selection.

C is the distractor - there is no universal 2-meter feeder length limit. Feeder length is constrained by acceptable signal loss (attenuation per meter) for the frequency band used, and longer runs are common in outdoor installations with appropriate low-loss cable.

Memory tip: Think "GAP" - Gain affects directivity, Antenna/feeder interfaces must match, and Pursuing max gain blindly is poor practice. Eliminate C by recalling that feeder length is limited by loss budget, not a fixed meter rule.

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