Updated: Dec 9, 2025 | Source: 2024-2028 Question Pool | Topic: E4B
E4B09E4B

Which of the following can be measured by a two-port vector network analyzer?

Deep Dive: E4B09

The correct answer is B: Filter frequency response. Which of the following can be measured by a two-port vector network analyzer is filter frequency response. VNAs can measure frequency response of two-port devices like filters. For amateur radio operators, this is important for test equipment. Understanding this helps when using network analyzers.

Why Other Answers Are Wrong

Option A (Phase noise): Incorrect. Phase noise isn't typically measured with VNA - VNAs measure frequency response. Phase noise isn't measured. Option C (Pulse rise time): Incorrect. Pulse rise time isn't measured with VNA - VNAs measure frequency response. Pulse rise time isn't measured. Option D (Forward power): Incorrect. Forward power isn't measured with VNA - VNAs measure S parameters and frequency response. Forward power isn't measured.

Exam Tip

Two-port VNA can measure = filter frequency response. Think 'V'ector 'N'etwork 'A'nalyzer = 'F'requency 'R'esponse. VNAs can measure frequency response of two-port devices like filters. Not phase noise, not pulse rise time, not forward power - just frequency response.

Memory Aid

Two-port VNA can measure = filter frequency response. Think 'V'ector 'N'etwork 'A'nalyzer = 'F'requency 'R'esponse. VNAs can measure frequency response of two-port devices like filters. Important for test equipment.

Real-World Example

A two-port vector network analyzer: It can measure filter frequency response. The VNA sends signals through the filter and measures the response, showing how the filter responds at different frequencies. This is what can be measured - filter frequency response.

Source & Coverage

Question Pool: 2024-2028 Question Pool

Subelement: E4B

Reference: 2024-2028 Question Pool · E4 - Amateur Practices

Key Concepts

Two-port vector network analyzer Filter frequency response VNA measurements Frequency response

Verified Content

Question from the official FCC Extra Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the E4B topic.