*Question G7C07:
What term specifies a filter’s attenuation inside its passband?*  

*Correct Answer is  A: Insertion loss*  

### AI Response: (may contain errors)  

The correct answer to the question is **A: Insertion loss**.

### Explanation of the Correct Answer:
- **Insertion loss** refers to the amount of signal power lost (attenuated) when a filter is inserted into a circuit, specifically within its passband. It quantifies how much of the input signal is lost as it passes through the filter, even when the filter is designed to allow certain frequencies to pass.

### Why the Other Choices are Incorrect:
- **B: Return loss**: This term measures how much of the signal is reflected back due to impedance mismatches at the input of the filter. It does not describe attenuation within the passband but rather the efficiency of power transfer into the filter.

- **C: Q**: The Q factor (quality factor) of a filter indicates how selective the filter is at its center frequency. A higher Q means a narrower bandwidth and sharper resonance, but it does not directly measure attenuation within the passband.

- **D: Ultimate rejection**: This term refers to the maximum attenuation a filter can achieve outside its passband, particularly at its stopband. It does not pertain to the attenuation experienced within the passband itself.

### Summary:
- Insertion loss is the key term for attenuation within the passband of a filter.
- Return loss, Q, and ultimate rejection describe different aspects of filter performance and do not apply to passband attenuation.

This understanding is crucial for evaluating filter performance in radio communications and ensuring effective signal processing.