Discuss Cisco 350-101 Exam Topic 4 Question 9

What is used for measuring gain on a Wi-Fi antenna?

Alength of the antenna

Bdecibels relative to dBi

Cvoltage against dBm

Dblend of analog and digital signals

Suggested Answer: B

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.

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23 comments · newest first

Cordelia 2 days ago

Yeah, B is the clear winner here.

Leslee 7 days ago

D) blend of analog and digital signals? That's off-topic.

Belen 12 days ago

C) voltage against dBm? Not really for gain measurement, right?

Wava 17 days ago

B is definitely the best choice. It gives a clear measurement.

France 22 days ago

A) length of the antenna seems relevant too, but not as precise.

Carrol 27 days ago

Agreed! dBi is crucial for measuring gain.

Cordelia 1 month ago

I think it's B) decibels relative to dBi. That's standard for antennas.

Rory 1 month ago

Exactly! Higher dBi means better performance.

Loreta 1 month ago

Right! Gain is all about efficiency, dBi is key.

Florencia 2 months ago

D) blend of analog and digital signals? Totally irrelevant here.

Kattie 2 months ago

C) voltage against dBm? Nah, that’s not right for gain.

Micheline 2 months ago

A) length of the antenna could matter, but not as much as dBi.

Rory 2 months ago

Agreed! dBi is standard for antennas. Very clear.

Loreta 2 months ago

I think it's B) decibels relative to dBi. Makes sense for gain measurement.

Cheryl 2 months ago

Totally agree with B! That's the standard measure.

Dalene 3 months ago

Wait, are we sure it's not C? Sounds kinda legit.

Rolland 3 months ago

B makes the most sense, right?

Alethea 3 months ago

I thought it was A) length of the antenna?

Becky 3 months ago

It's definitely B) decibels relative to dBi.

Arlie 3 months ago

I don't think voltage against dBm is correct for measuring gain; it seems more about the antenna's efficiency in dBi.

Deane 3 months ago

I feel like the length of the antenna might play a role, but I can't recall if it's the main measurement for gain.

Art 4 months ago

I remember practicing a question about antenna gain, and I think it was definitely related to dBi.

Malinda 4 months ago

I think gain is usually measured in decibels, but I'm not sure if it's specifically dBi or dBm.

Cisco 350-101 Exam - Topic 4 Question 9 Discussion