Which S parameter represents input port return loss or reflection coefficient (equivalent to VSWR)?
The correct answer is A: S11. Which S parameter represents input port return loss or reflection coefficient (equivalent to VSWR) is S11. S11 is the input reflection coefficient. For amateur radio operators, this is important for RF measurements. Understanding this helps when using network analyzers.
Exam Tip
S parameter for input reflection = S11. Think 'S'11 = 'S'ignal 'R'eflected at port '1' (input). S11 is the input reflection coefficient (return loss/VSWR). Not S12 (reverse), not S21 (forward gain), not S22 (output) - just S11.
Memory Aid
"S parameter for input reflection = S11. Think 'S'11 = 'I'nput 'R'eflection. S11 is the input reflection coefficient (return loss/VSWR). Important for RF measurements."
Real-World Application
S parameters: S11 represents input port return loss or reflection coefficient (equivalent to VSWR). S11 measures how much signal is reflected at the input port. This is the parameter - S11 is input reflection.
Key Concepts
Why Other Options Are Wrong
Option B (S12): Incorrect. S12 is reverse transmission, not input reflection - S11 is input reflection. S12 is reverse.
Option C (S21): Incorrect. S21 is forward gain, not input reflection - S11 is input reflection. S21 is forward gain.
Option D (S22): Incorrect. S22 is output reflection, not input reflection - S11 is input reflection. S22 is output reflection.
题目解析
The correct answer is A: S11. Which S parameter represents input port return loss or reflection coefficient (equivalent to VSWR) is S11. S11 is the input reflection coefficient. For amateur radio operators, this is important for RF measurements. Understanding this helps when using network analyzers.
考试技巧
S parameter for input reflection = S11. Think 'S'11 = 'S'ignal 'R'eflected at port '1' (input). S11 is the input reflection coefficient (return loss/VSWR). Not S12 (reverse), not S21 (forward gain), not S22 (output) - just S11.
记忆口诀
S parameter for input reflection = S11. Think 'S'11 = 'I'nput 'R'eflection. S11 is the input reflection coefficient (return loss/VSWR). Important for RF measurements.
实际应用示例
S parameters: S11 represents input port return loss or reflection coefficient (equivalent to VSWR). S11 measures how much signal is reflected at the input port. This is the parameter - S11 is input reflection.
错误选项分析
Option B (S12): Incorrect. S12 is reverse transmission, not input reflection - S11 is input reflection. S12 is reverse. Option C (S21): Incorrect. S21 is forward gain, not input reflection - S11 is input reflection. S21 is forward gain. Option D (S22): Incorrect. S22 is output reflection, not input reflection - S11 is input reflection. S22 is output reflection.
知识点
S parameter, Input port return loss, Reflection coefficient, VSWR, S11
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.