What term specifies a filter’s attenuation inside its passband?
The correct answer is A: Insertion loss. The term that specifies a filter's attenuation inside its passband is insertion loss. Insertion loss is the signal loss when the filter is inserted into a circuit. For amateur radio operators, this is important for filter performance. Understanding this helps when evaluating filters.
Exam Tip
Filter passband attenuation = insertion loss. Think 'I'nsertion 'L'oss = 'I'nside 'L'oss (passband). Insertion loss is the signal loss when filter is inserted into circuit. Not return loss (SWR), not Q (selectivity), not ultimate rejection (stopband) - just insertion loss.
Memory Aid
"Filter passband attenuation = insertion loss. Think 'I'nsertion 'L'oss = 'I'nside 'L'oss. Insertion loss is the signal loss when filter is inserted into circuit. Specifies passband attenuation."
Real-World Application
A filter has 1 dB insertion loss in its passband. This means when you insert the filter, the signal is attenuated by 1 dB even in the passband (where signals should pass). Insertion loss is the filter's own loss - lower is better. This is how passband attenuation is specified.
Key Concepts
Why Other Options Are Wrong
Option B (Return loss): Incorrect. Return loss is about reflected power (SWR), not passband attenuation. Return loss is for impedance matching, not filter attenuation.
Option C (Q): Incorrect. Q is the quality factor (selectivity), not passband attenuation. Q measures how selective a filter is, not its loss.
Option D (Ultimate rejection): Incorrect. Ultimate rejection is about stopband rejection (outside passband), not passband attenuation. Ultimate rejection is for out-of-band signals.
题目解析
The correct answer is A: Insertion loss. The term that specifies a filter's attenuation inside its passband is insertion loss. Insertion loss is the signal loss when the filter is inserted into a circuit. For amateur radio operators, this is important for filter performance. Understanding this helps when evaluating filters.
考试技巧
Filter passband attenuation = insertion loss. Think 'I'nsertion 'L'oss = 'I'nside 'L'oss (passband). Insertion loss is the signal loss when filter is inserted into circuit. Not return loss (SWR), not Q (selectivity), not ultimate rejection (stopband) - just insertion loss.
记忆口诀
Filter passband attenuation = insertion loss. Think 'I'nsertion 'L'oss = 'I'nside 'L'oss. Insertion loss is the signal loss when filter is inserted into circuit. Specifies passband attenuation.
实际应用示例
A filter has 1 dB insertion loss in its passband. This means when you insert the filter, the signal is attenuated by 1 dB even in the passband (where signals should pass). Insertion loss is the filter's own loss - lower is better. This is how passband attenuation is specified.
错误选项分析
Option B (Return loss): Incorrect. Return loss is about reflected power (SWR), not passband attenuation. Return loss is for impedance matching, not filter attenuation. Option C (Q): Incorrect. Q is the quality factor (selectivity), not passband attenuation. Q measures how selective a filter is, not its loss. Option D (Ultimate rejection): Incorrect. Ultimate rejection is about stopband rejection (outside passband), not passband attenuation. Ultimate rejection is for out-of-band signals.
知识点
Filter attenuation, Insertion loss, Passband, Filter performance
Verified Content
Question from official FCC General Class question pool. Explanation reviewed by licensed amateur radio operators.