6 SatCom Flashcards
What are the 4 components of SatCom?
- Transmitter
- Repeater (Satellite)
- Receiver
- Medium
Which frequency is most affected by Free Space Losses?
Higher frequency
What frequency ranges does SatCom utilise (inc freq.)?
UHF: 300 MHz- 3 GHz
SHF: 3 GHz - 30 GHz
EHF: 30 GHz - 300 GHz
Why do we not use frequencies below 100 MHz for SatCom?
EM waves are unable to penetrate the ionosphere
Why do we not use frequencies above 40 GHz?
Atmospheric attenuation/absorption prevents transmission to the satellite
Higher frequency SatCom does what to the beam width?
Narrows it
In terms of SatCom beam coverage. Does higher or lower frequency give increase coverage?
Lower
In increasing frequency. Name the SatCom bands
UHF, L, S, C, X, Ku, K, Ka
X band SatCom is in what Em band?
SHF
Ka SatCom is in what EM band?
EHF
Ku SatCom is in what EM band?
SHF
Increasing the frequency of SatCom does what to the Gain(directivity) of the signal?
Increases it
Having smaller SatCom beam widths increases the chance of what error occurring?
De-pointing error
Match:
UHF, SHF, EHF with Highs Capacity, Mobile Comms, Robust
UHF - Mobile Comms
SHF - High Capacity
EHF - Robust
Advantages of higher vs lower frequencies when using SatCom
- Enhanced data rates
- Enhanced bandwidth
- Ability to employ anti-jam techniques
- Less susceptible to scintillation
- Reduced beam coverage
