1. Chapter 3 Radio Frequency Components, Measurements, and Mathematics

2. Key Terms & Concepts 3 Basic Requirements for Communication
Two or more devices want to communicate
Medium or method for them to communicate
Set of rules for them to use

3. Key Terms & Concepts Transmitter Antenna
Generates signal at specific frequency
Determines amplitude (power level) of signal
Antenna
Collects AC signal that receives from transmitter
Directs, or radiates, RF waves away from the antenna in a specific pattern

4. Key Terms & Concepts Receiver Intentional Radiator (IR)
Receives the signal from the antenna and translates the signal into 1s and 0s
Intentional Radiator (IR)
Specifically designed to generate RF
Consists of all components from transmitter to antenna, excluding antenna

5. Key Terms & Concepts Equivalent Isotropically Radiated Power (EIRP)
Highest RF signal strength transmitted from antenna
Focuses the RF generated by the IR and makes it stronger

6. Key Terms & Concepts Units of Power Watt Milliwatt (mW)
1 Watt = 1 ampere (amp) of current flowing at 1 volt
Amp is current
Voltage is pressure generated
Amount of watts generated = volts X amps
Milliwatt (mW)
1/1,000 of a watt
Decibels relative to 1 milliwatt (dBm)
Compares signal to 1 milliwatt of power
0 dBm = 1 milliwatt

7. Key Terms & Concepts Units of Comparison Milliwatts Decibel change .01
Decibel (dB)
Represents difference btw 2 values
Decibels isotropic (dBi)
Gain or increase of power from an antenna when compared to what an isotropic radiator would generate
Milliwatts
Decibel change
.01
-20 .1
-10 1 10
+10
100
+20
1000
+30
10000
+40

8. Key Terms & Concepts Units of Comparison Decibels dipole (dBd)
Increase in gain of an antenna when it is compared to the signal of a dipole antenna
If antenna has value of 3 dBd, it is 3 dB greater than a dipole antenna