Radio Frequency Fundamentals (560-15-2)
Which of the provided voltage standing wave ratios (VSWR) shown here is best for transferring radio frequency (RF) energy between connections?
1.2:1 (Voltage Standing Wave Ratio > Voltage Standing Wave Ratio Measurements)
What unit of measurement is used to express the gain of an antenna?
Decibels isotropic (dBi). (Radio Frequency Mathematics > Gain and Loss Measurements > dBi)
In what manner do radio waves propagate (move) away from the source (antenna)?
In a straight line in all directions at once. (Radio Frequencies > Introduction to Radio Frequencies)
Given an access point (AP) with 100 milliwatts (mW) of output power connected through a cable with 3 decibels (dB) of loss to the antenna with a 10 decibels isotropic (dBi) gain, what is the approximate Equivalent Isotropically Radiated Power (EIRP) level from the antenna in mW?
500 mW. (Radio Frequency Mathematics > Gain and Loss Measurements > dBm)
How does radio frequency line-of-sight (RF LOS) differ from visual LOS?
RF LOS is accompanied by a Fresnel zone, a series of concentric ellipsoid-shaped areas around the visual LOS path. (Principles of Antennas > Wireless Local Area Network Antenna Principles > Fresnel Zone)
What are some measures that can be taken to prevent high voltage standing wave ratios (VSWR) in transmitters and receivers?
Tighten connections between cables and connectors and use impedance-matched hardware throughout. (Voltage Standing Wave Ratio > Voltage Standing Wave Ratio Measurements >Solutions to Excessive VSWR Impedance)
A transmitter outputs 100 milliwatts (mW). An antenna cable connects the transmitter to an amplifier, and the power into the amplifier's input measures 50 mW. The amplifier increases the signal to the original transmitter's power level and sends the signal to the antenna. The antenna receives the signal from the amplifier at 75 mW, and then transmits at 150 mW. What is the intentional radiator's (IR) power level in this radio frequency (RF) circuit?
75 mW. (Radio Frequency Mathematics > Gain and Loss Measurements > dBm)
Which one of the following radio frequency (RF) behaviors is defined as "the bending of a wave as it passes through a medium of different density"?
Refraction (Radio Frequencies > RF Behaviors > Refraction)
Why is the Fresnel zone important to the integrity of the radio frequency (RF) link or path?
The Fresnel zone defines an area around the RF line-of-sight (RF LOS) that can introduce RF signal interference if blocked. (Principles of Antennas > Wireless Local Area Network Antenna Principles > Fresnel Zone)
What is Equivalent Isotropically Radiated Power (EIRP)?
The power actually radiated by the antenna element. (Principles of Antennas > Equivalent Isotropic Radiated Power)
