From SEDSWiki

Subsystem Notes as of SEDSIC '07

(Assumption: Satellite will be in Low Earth Orbit)

• Frequency range (we’re using 420 MHz)
  • UHF (300 MHz – 3 GHz)
  • Availability of equipment (transmitter/receiver)
  • Smaller antenna structure
• Modulation
  • Phase Shift-Keying
    • DPSK, a variation that is simpler to implement, but produces erroneous demodulations
    • QPSK
    • BPSK
      • Transmission bit rate is higher
      • Lower bandwidth
  • Frequency Shift-Keying
    • High power, high spectral efficiency (?)
    • High bandwidth
    • Extensively used by most CubeSats
    • Availability of equipment
    • Slower in transmission.
    • Reception setup is simpler
    • FSK is more power efficient
  • Amplitude Shift-Keying
    • linear and sensitive to atmospheric noise, distortions, propagation conditions on different route
    • requires excessive band-width, waste of power
    • modulation and demodulation is relatively inexpensive
    • used for digital data transfer over optical fiber
      • look into redundancy systems
      • Doppler effect
• Antenna
  • Dipole
  • Bi-directional
    • Lower gain than the other two (1.64)
    • Smaller volume – one element
    • Simple to design
    • Seems to be best option
  • Log-Periodic Antenna
    • Lower in gain
    • Broad bandwidth
    • More space
    • More mass
• Transceiver – Transmitter / Receiver
  • Weight
  • Link budget
  • Power budget, frequency, Antenna gain
• Terminal Node Controller (TNC)
  • Which component to use.
  • What are the parameters? Weight, power, volume
• Amplifier
  • Which component to use.
  • What are the parameters? Weight, power, volume
  • Necessity
    • Not very necessary
    • Power drain
    • Batteries will need to be bigger/heavier