*Question G4D09:
What frequency range is occupied by a 3 kHz USB signal with the displayed carrier frequency set to 14.347 MHz?*  

*Correct Answer is  B: 14.347 MHz to 14.350 MHz*  

### AI Response: (may contain errors)  

To determine the frequency range occupied by a 3 kHz Upper Sideband (USB) signal with a carrier frequency of 14.347 MHz, we can use the following approach:

1. **Understanding USB**: In USB, the signal occupies frequencies above the carrier frequency. Therefore, the bandwidth of the signal extends from the carrier frequency up to the bandwidth limit.

2. **Calculating the Frequency Range**: 
   - The carrier frequency is $14.347 \text{ MHz}$.
   - The bandwidth of the USB signal is $3 \text{ kHz}$, which is equivalent to $0.003 \text{ MHz}$.
   - The upper limit of the frequency range can be calculated as:
     $$ \text{Upper Limit} = \text{Carrier Frequency} + \text{Bandwidth} = 14.347 \text{ MHz} + 0.003 \text{ MHz} = 14.350 \text{ MHz} $$

   Thus, the frequency range occupied by the signal is from $14.347 \text{ MHz}$ to $14.350 \text{ MHz}$.

### Why the Correct Answer is Correct:
- The correct answer is **A: 14.347 MHz to 14.350 MHz** because it accurately reflects the carrier frequency plus the bandwidth of the USB signal.

### Why the Other Choices are Incorrect:
- **B: 14.347 MHz to 14.350 MHz**: This is actually the correct range, but it seems to be a typographical error in the answer choices. It should be noted that this is the same as the correct answer.
- **C: 14.344 MHz to 14.347 MHz**: This range is below the carrier frequency and does not account for the USB nature of the signal, which occupies frequencies above the carrier.
- **D: 14.3455 MHz to 14.3485 MHz**: This range is also incorrect as it does not encompass the full bandwidth of the USB signal starting from the carrier frequency.

### Summary:
- The frequency range for a 3 kHz USB signal with a carrier frequency of 14.347 MHz is from **14.347 MHz to 14.350 MHz**.
- Remember that USB signals occupy frequencies above the carrier frequency, and the bandwidth is added to the carrier to find the upper limit.