*Question G7C01:
What circuit is used to select one of the sidebands from a balanced modulator?*  

*Correct Answer is  B: Filter*  

### AI Response: (may contain errors)  

In a single sideband (SSB) transmitter, a balanced modulator is used to generate a double sideband suppressed carrier (DSB-SC) signal. This signal contains both the upper and lower sidebands, but we only want one of them for SSB transmission.

1. **Correct Answer: Filter**  
   - A filter is used to select one of the sidebands from the DSB-SC signal produced by the balanced modulator. By using a bandpass filter, you can remove the unwanted sideband and the suppressed carrier, leaving only the desired sideband (either upper or lower) for transmission.

2. **Why the Other Choices are Incorrect:**
   - **Carrier Oscillator:** This generates the carrier frequency but does not select sidebands. It is used in the modulation process but not in the sideband selection.
   - **IF Amplifier:** An intermediate frequency (IF) amplifier amplifies signals at a specific intermediate frequency but does not select sidebands.
   - **RF Amplifier:** An RF amplifier amplifies the radio frequency signal for transmission but does not perform sideband selection.

In summary, the filter is crucial in isolating the desired sideband from the output of the balanced modulator, making it the correct choice for this question.