What is used to control the attenuation of RF signals by a PIN diode?
The correct answer is A: Forward DC bias current. What is used to control the attenuation of RF signals by a PIN diode is forward DC bias current. PIN diode attenuation is controlled by forward bias current. For amateur radio operators, this is important for RF switching. Understanding this helps when using PIN diodes.
Exam Tip
PIN diode attenuation control = forward DC bias current. Think 'P'IN 'D'iode 'A'ttenuation = 'F'orward 'D'C 'B'ias. PIN diode attenuation is controlled by forward bias current. Not RF reference voltage, not reverse voltage, not coupling capacitor - just forward DC bias current.
Memory Aid
"PIN diode attenuation control = forward DC bias current. Think 'P'IN 'D'iode = 'F'orward 'B'ias. PIN diode attenuation is controlled by forward bias current. Important for RF switching."
Real-World Application
Controlling the attenuation of RF signals by a PIN diode: Forward DC bias current is used. By varying the forward bias current, you can control how much the PIN diode attenuates the RF signal. This is what's used - forward DC bias current.
Key Concepts
Why Other Options Are Wrong
Option B: Incorrect. Variable RF reference voltage isn't used - forward DC bias current controls attenuation. RF reference voltage isn't used.
Option C: Incorrect. Reverse voltage larger than RF signal isn't used - forward DC bias current controls attenuation. Reverse voltage isn't used.
Option D: Incorrect. Capacitance of RF coupling capacitor isn't used - forward DC bias current controls attenuation. Coupling capacitor isn't used.
题目解析
The correct answer is A: Forward DC bias current. What is used to control the attenuation of RF signals by a PIN diode is forward DC bias current. PIN diode attenuation is controlled by forward bias current. For amateur radio operators, this is important for RF switching. Understanding this helps when using PIN diodes.
考试技巧
PIN diode attenuation control = forward DC bias current. Think 'P'IN 'D'iode 'A'ttenuation = 'F'orward 'D'C 'B'ias. PIN diode attenuation is controlled by forward bias current. Not RF reference voltage, not reverse voltage, not coupling capacitor - just forward DC bias current.
记忆口诀
PIN diode attenuation control = forward DC bias current. Think 'P'IN 'D'iode = 'F'orward 'B'ias. PIN diode attenuation is controlled by forward bias current. Important for RF switching.
实际应用示例
Controlling the attenuation of RF signals by a PIN diode: Forward DC bias current is used. By varying the forward bias current, you can control how much the PIN diode attenuates the RF signal. This is what's used - forward DC bias current.
错误选项分析
Option B: Incorrect. Variable RF reference voltage isn't used - forward DC bias current controls attenuation. RF reference voltage isn't used. Option C: Incorrect. Reverse voltage larger than RF signal isn't used - forward DC bias current controls attenuation. Reverse voltage isn't used. Option D: Incorrect. Capacitance of RF coupling capacitor isn't used - forward DC bias current controls attenuation. Coupling capacitor isn't used.
知识点
Control attenuation, RF signals, PIN diode, Forward DC bias current
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.