Cisco 350-101 Exam - Topic 5 Question 5 Discussion

Wi-Fi antenna gain is measured in dBi, meaning decibels referenced to an isotropic radiator. Cisco's Wireless RF Reference Guide states that antennas have gain measured in decibels relative to isotropic gain, or dBi, and further explains that antenna gain is a ratio comparing the gain of a specific antenna to a theoretical isotropic antenna. Cisco's RF design documentation also defines dBi as the power gain rating of antennas, where real antennas are compared to an isotropic antenna that radiates the same power density equally in all directions.

Option B is therefore the correct selection, although the technically precise phrase is decibels relative to isotropic, abbreviated dBi. Antenna length can influence resonance and design, but it is not the measurement unit for gain. Voltage against dBm is incorrect because dBm references absolute power relative to 1 milliwatt, not antenna gain. Analog/digital signal blending is unrelated to RF antenna performance. Reference topics: RF Fundamentals --- antenna gain, dBi, isotropic radiator, EIRP, antenna patterns, and WLAN RF design.