EM Spectrum
Decibel
Antenna
Spread Spectrum/SATCOM
Misc
100
Longest wavelength in EM spectrum. Heinrich Hertz proved existence with spark gap antennas.
What are radio waves?
100
This dB difference represents gain of 100% or loss of 50%.
What is +3 dB (2x) and -3 dB (.5x)?
100
Also known as a tank circuit.
What is LC circuit?
100
This technique decreases signal power density; causes signal to be at or below background noise level. Must know the PRN code to access information.
What is Direct Sequence?
100
Meaning of GIG.
What is Global Information Grid: globally interconnected set of information capabilities and processing to manage data on demand for warfighters and policy makers?
200
These have 380 nm and 700 nm wavelengths.
What is violet and red (visible light)?
200
Measurement of gain an antenna possesses when compared to a dipole antenna at the same frequency. Used to describe gain for antennas operating under 1 GHz.
What is decibel dipole (dBd)?
200
Series resonant circuit results in this much impedance at the resonant frequency.
What is very little impedance?
200
This multiple access method is widely used in TV, radio broadcasts, SATCOM transponders, and any radio where channels or users are designated by frequency. Assigns a different frequency to each user.
What is Frequency Division Multiple Access (FDMA)?
200
This the temporary partial or total elimination of a space system's capabilities usually without physical damage.
What is denial?
300
Produced by hottest & most energetic objects in universe and nuclear explosions, lighting, and radioactive decay on earth.
What are Gamma Rays?
300
Gain measurement for antennas above 1 GHz.
What is decibel isotropic (dBi)?
300
This type of circuit has the highest impedance at resonant frequency, acting as a filter for the desired frequency. All other frequencies see the circuit as a shortcut to ground.
What is parallel resonant circuits?
300
This multiple access method assigns available channel capacity to a station from a bandwidth pool on demand; first come, first served.
What is Demand Assigned Multiple Access (DAMA)?
300
This RF band is used by AF Wideband Global (WGS) SATCOM broadband comm satellites.
What is Ka-Band (SHF, 27-30 GHz)?
400
Also known as longwave. Used for aircraft beacons, long range (LORAN) navigation and weather systems. 30 kHz - 300 kHz.
What is Low Frequency? (LF)
400
This is determined by adding antenna gain (dBi) plus the amount of power (dBm) applied to the antenna.
What is Effective Isotropic Radiated Power (EIRP)?
400
If this ratio is low, there is efficient energy transfer between components (radio, antenna, and physical transmission medium). They have the same impedance. Signal strength is high.
What is Voltage Standing Wave Ratio (VSWR)?
400
This segment of SATCOM is the area of EM spectrum between ground terminal and satellite in which signals pass (includes orbits and satellite coverage).
What is Space segment?
400
This is antenna nulling.
What is the satellite operator reduces (nulls) antenna signal to a spot beam, & the antenna ignores anything outside the footprint specified by controller?
500
This band of RF frequencies (8-12 GHz) is the workhorse band for military broadband communications and used in missile defense radars.
What is X-Band (SHF, 8-12 Ghz)?
500
This is proportional to the square of the distance between the Tx and Rx and also proportional to the square of the frequency of the radio signal.
What is Free-Space Path Loss (FSPL)?
500
This type of antenna radiates energy equally in all directions.
What is isotropic antenna?
500
What are the four primary systems (satellites) of the MILSATCOM architecture ?
What is UHF Follow-on, SHF DSCS, Wideband Global SATCOM (WGS), and EHF Milstar
500
This squadron provides OSC and SSA capabilities to achieve rapid, flexible, and versatile effects supporting global and theater campaigns. Lt Luft's squadron.
What is 4th Space Control?
M
e
n
u