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Compared with the GaAs and InP based HBTs, the Si/SiGe HBT has a lower cutoff frequency because of:


18. Compared with the GaAs and InP based HBTs, the Si/SiGe HBT has a lower cutoff frequency because of:

  1. Lower mobilities in Si
  2. Higher mobilities in Si
  3. Lower mobilities in Ge
  4. Higher mobilities in Ge
Answer: Option A
Solution: In case of mobilty
GaAs > Ge> Si
 the Si/SiGe HBT has a lower cutoff frequency because Si has lower cutoff mobilities (i.e., lower electron and hole mobilities)
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