CWDP Antenna Design and Placement Flashcards

In the US, the FCC limits maximum EIRP for point-to-multipoint 5 GHz outdoor links to which value?

Answer: 36 dBm

The FCC limits point-to-multipoint EIRP in the 5 GHz UNII bands to 36 dBm for outdoor use.

What is the half-power beamwidth (HPBW) of an antenna?

Answer: The angle at which the antenna gain drops to 3 dB below peak

HPBW is the angular width measured between the two points where gain falls to half (-3 dB) of its maximum value.

A designer wants to mount antennas in the ceiling of a 10,000 sq ft warehouse. What spacing consideration is most critical?

Answer: Ensuring overlap of approximately 15–20% between cell edges

A 15–20% cell-edge overlap ensures seamless roaming and prevents coverage gaps in large open spaces.

Which cable type is preferred for short indoor antenna runs to minimize insertion loss?

Answer: LMR-400

LMR-400 has lower attenuation per foot than RG-58 or RG-8, making it preferred for minimizing cable losses.

What effect does each 3 dB increase in antenna gain have on the effective coverage radius (assuming free-space path loss)?

Answer: Increases radius by approximately 41%

A 3 dB gain increase doubles the power density, which increases the free-space coverage radius by roughly 41%.

Which antenna characteristic describes its ability to reject interference from directions outside its main lobe?

Answer: Front-to-back ratio

The front-to-back ratio indicates how much more gain an antenna has in its main direction versus the opposite direction.