Question
Which of the following is used to measure SWR?
Answer Options
- A) Directional wattmeter
- B) Vector network analyzer
- C) Antenna analyzer
- D) All these choices are correct
Correct Answer: D
Explanation
Standing Wave Ratio (SWR) is a dimensionless measure of how well a load (like an antenna) is matched to the characteristic impedance of the feed line (usually 50 ohms). Because SWR is a critical parameter in amateur radio, there are several different types of instruments capable of measuring it, each offering different levels of detail and convenience.
Instruments used to measure SWR include a directional wattmeter (which measures forward and reflected power to calculate SWR), a Vector Network Analyzer (VNA) (which measures impedance and calculates SWR as a secondary function), and an antenna analyzer (which directly measures impedance and calculates SWR across a band). Therefore, all these choices are correct.
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