RF Principles Flashcards
7 cards from real ACMA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 RF Principles flashcards as text
What effect does increasing the frequency of an RF signal have on its free-space path loss?
Answer: Path loss increases because higher frequencies attenuate more over the same distance
Higher frequencies experience greater free-space path loss over the same distance, which is why 5 GHz links have shorter range than 2.4 GHz links at the same power level.
In RF terminology, what does the term 'noise floor' refer to?
Answer: The background level of unwanted RF energy present in the environment
The noise floor is the sum of all background RF interference and thermal noise present in the environment, measured in dBm, and defines the minimum signal level that can be detected.
What is the relationship between wavelength and frequency of an RF signal?
Answer: Wavelength decreases as frequency increases
Wavelength and frequency are inversely proportional: as frequency increases, wavelength decreases (λ = c/f, where c is the speed of light).
Which of the following materials causes the greatest RF signal attenuation?
Answer: Reinforced concrete
Reinforced concrete contains metal rebar and dense material, causing the highest RF attenuation among common building materials.
What is RF absorption in the context of wireless networking?
Answer: The conversion of RF signal energy into heat as it passes through a material
RF absorption occurs when materials convert RF energy into heat as the signal passes through them, reducing the signal's strength on the other side.
What is the purpose of a site survey prior to deploying a wireless network?
Answer: To assess the RF environment, identify interference sources, and determine optimal AP placement
A site survey evaluates the physical environment, existing RF interference, and building materials to plan optimal AP placement and channel configuration.
Which of the following describes the 'Rule of 10s and 3s' in RF power calculations?
Answer: A 10 dB increase equals 10x power; a 3 dB increase equals approximately 2x power
The Rule of 10s and 3s states that a 10 dB change represents a 10-fold change in power and a 3 dB change represents approximately a 2-fold change in power.