Lesson 10

Which of the voltage standing wave ratios (VSWR) shown below is best for transferring radio frequency (RF) energy between connections?

1.2:1

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

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 milliwatts (mW)?

500 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 IR power level in this radio frequency (RF) circuit?

75 mW.

What unit of measurement is used to express the gain of an antenna?

Decibels over, or under 1 milliwatt (mW).

In what manner do radio waves propagate (move) away from the source (antenna)?

In a straight line in all directions at once.

How does radio frequency line-of-sight (RF LOS) differ from visual LOS?

LOS is accompanied by a Fresnel Zone, a series of concentric ellipsoid-shaped areas around the visual LOS path.

The Why is the Fresnel Zone important to the integrity of the 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.

What is Equivalent Isotropically Radiated Power (EIRP)?

The The power actually radiated by the antenna element.

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.