Why is an anti-aliasing filter required in a decimator?
The correct answer is A: It removes high-frequency signal components that would otherwise be reproduced as lower frequency components. Why is an anti-aliasing filter required in a decimator is that it removes high-frequency signal components that would otherwise be reproduced as lower frequency components. Anti-aliasing prevents aliasing when reducing sample rate. For amateur radio operators, this is important for digital signal processing. Understanding this helps when working with decimators.
Exam Tip
Anti-aliasing filter in decimator = removes high-frequency components that would be reproduced as lower frequencies. Think 'A'nti-'A'liasing = 'A'voids 'A'liasing (removes high frequencies). Anti-aliasing prevents aliasing when reducing sample rate. Not peaking response, not low-frequency removal, not notching sampling frequency - just removes high frequencies to prevent aliasing.
Memory Aid
"Anti-aliasing filter in decimator = removes high-frequency components that would be reproduced as lower frequencies. Think 'A'nti-'A'liasing = 'P'revents aliasing. Anti-aliasing prevents aliasing when reducing sample rate. Important for digital signal processing."
Real-World Application
An anti-aliasing filter required in a decimator: It removes high-frequency signal components that would otherwise be reproduced as lower frequency components. Without the filter, aliasing would occur when the sample rate is reduced. This is the reason - prevents aliasing.
Key Concepts
Why Other Options Are Wrong
Option B: Incorrect. Peaking response of decimator isn't the reason - anti-aliasing removes high frequencies to prevent aliasing. Peaking response isn't the reason.
Option C: Incorrect. Removing low-frequency components to eliminate DC restoration isn't the reason - anti-aliasing removes high frequencies to prevent aliasing. Low-frequency removal isn't the reason.
Option D: Incorrect. Notching out sampling frequency isn't the reason - anti-aliasing removes high frequencies to prevent aliasing. Notching sampling frequency isn't the reason.
题目解析
The correct answer is A: It removes high-frequency signal components that would otherwise be reproduced as lower frequency components. Why is an anti-aliasing filter required in a decimator is that it removes high-frequency signal components that would otherwise be reproduced as lower frequency components. Anti-aliasing prevents aliasing when reducing sample rate. For amateur radio operators, this is important for digital signal processing. Understanding this helps when working with decimators.
考试技巧
Anti-aliasing filter in decimator = removes high-frequency components that would be reproduced as lower frequencies. Think 'A'nti-'A'liasing = 'A'voids 'A'liasing (removes high frequencies). Anti-aliasing prevents aliasing when reducing sample rate. Not peaking response, not low-frequency removal, not notching sampling frequency - just removes high frequencies to prevent aliasing.
记忆口诀
Anti-aliasing filter in decimator = removes high-frequency components that would be reproduced as lower frequencies. Think 'A'nti-'A'liasing = 'P'revents aliasing. Anti-aliasing prevents aliasing when reducing sample rate. Important for digital signal processing.
实际应用示例
An anti-aliasing filter required in a decimator: It removes high-frequency signal components that would otherwise be reproduced as lower frequency components. Without the filter, aliasing would occur when the sample rate is reduced. This is the reason - prevents aliasing.
错误选项分析
Option B: Incorrect. Peaking response of decimator isn't the reason - anti-aliasing removes high frequencies to prevent aliasing. Peaking response isn't the reason. Option C: Incorrect. Removing low-frequency components to eliminate DC restoration isn't the reason - anti-aliasing removes high frequencies to prevent aliasing. Low-frequency removal isn't the reason. Option D: Incorrect. Notching out sampling frequency isn't the reason - anti-aliasing removes high frequencies to prevent aliasing. Notching sampling frequency isn't the reason.
知识点
Anti-aliasing filter, Required in decimator, Removes high-frequency signal components, Reproduced as lower frequency components
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.