What characteristic of a PIN diode makes it useful as an RF switch?
The correct answer is D: Low junction capacitance. What characteristic of a PIN diode makes it useful as an RF switch is low junction capacitance. Low capacitance allows PIN diodes to work well as RF switches. For amateur radio operators, this is important for RF switching. Understanding this helps when using PIN diodes.
Exam Tip
PIN diode useful as RF switch = low junction capacitance. Think 'P'IN 'D'iode = 'L'ow 'C'apacitance. Low capacitance allows PIN diodes to work well as RF switches. Not high breakdown, not power dissipation, not forward voltage control - just low junction capacitance.
Memory Aid
"PIN diode useful as RF switch = low junction capacitance. Think 'P'IN 'D'iode = 'L'ow 'C'apacitance. Low capacitance allows PIN diodes to work well as RF switches. Important for RF switching."
Real-World Application
A PIN diode as an RF switch: It's useful because of low junction capacitance. Low capacitance means the diode doesn't affect the RF signal when off, making it a good switch. This is the characteristic - low junction capacitance.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Extremely high reverse breakdown voltage isn't the characteristic - low junction capacitance is. High breakdown isn't the characteristic.
Option B: Incorrect. Ability to dissipate large amounts of power isn't the characteristic - low junction capacitance is. Power dissipation isn't the characteristic.
Option C: Incorrect. Reverse bias controls forward voltage drop isn't the characteristic - low junction capacitance is. Forward voltage control isn't the characteristic.
题目解析
The correct answer is D: Low junction capacitance. What characteristic of a PIN diode makes it useful as an RF switch is low junction capacitance. Low capacitance allows PIN diodes to work well as RF switches. For amateur radio operators, this is important for RF switching. Understanding this helps when using PIN diodes.
考试技巧
PIN diode useful as RF switch = low junction capacitance. Think 'P'IN 'D'iode = 'L'ow 'C'apacitance. Low capacitance allows PIN diodes to work well as RF switches. Not high breakdown, not power dissipation, not forward voltage control - just low junction capacitance.
记忆口诀
PIN diode useful as RF switch = low junction capacitance. Think 'P'IN 'D'iode = 'L'ow 'C'apacitance. Low capacitance allows PIN diodes to work well as RF switches. Important for RF switching.
实际应用示例
A PIN diode as an RF switch: It's useful because of low junction capacitance. Low capacitance means the diode doesn't affect the RF signal when off, making it a good switch. This is the characteristic - low junction capacitance.
错误选项分析
Option A: Incorrect. Extremely high reverse breakdown voltage isn't the characteristic - low junction capacitance is. High breakdown isn't the characteristic. Option B: Incorrect. Ability to dissipate large amounts of power isn't the characteristic - low junction capacitance is. Power dissipation isn't the characteristic. Option C: Incorrect. Reverse bias controls forward voltage drop isn't the characteristic - low junction capacitance is. Forward voltage control isn't the characteristic.
知识点
PIN diode, Useful as RF switch, Low junction capacitance, RF switching
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.