Antennas – Match each item to its characteristic or frequency range List I (Antenna / Term) A. Loop antenna B. Folded dipole C. SWR of 1 (standing-wave ratio equals 1) D. VHF band List II (Property / Meaning) Flat line indication on an SWR meter (perfect match) 300 Ω input impedance (balanced) Sharp broadside null in the radiation pattern 30 to 300 MHz frequency range Choose the correct mapping from List I to List II.

Introduction / Context:This matching question checks foundational antenna knowledge: common feed impedances, pattern features, perfect-match indicators, and standard frequency bands used in radio and TV systems. Knowing these “textbook” facts helps when selecting antennas and reading measurement instruments such as SWR meters.

Given Data / Assumptions:

• Loop antennas (small loops) exhibit characteristic nulls and broadside pattern behavior.
• A folded dipole is a classic 300 Ω balanced radiator, often used with twin-lead.
• SWR = 1 indicates a perfect impedance match (no reflection).
• VHF band is the internationally accepted 30 to 300 MHz range.

Concept / Approach:

Map each antenna/term to the best-known property: loop antennas have a sharp broadside null; folded dipole is about 300 Ω; SWR of 1 corresponds to a flat-line indication on an SWR meter (no standing waves); VHF spans 30–300 MHz. These pairings are standard across antenna references and exam syllabi.

Step-by-Step Solution:

Verification / Alternative check:

Cross-check with standard antenna texts: folded dipole impedance ≈ 300 Ω; SWR = 1.0 means reflection coefficient 0; VHF is 30–300 MHz; small loops present deep broadside nulls useful for direction finding.

Why Other Options Are Wrong:

Assigning 300 Ω to the loop or calling VHF outside 30–300 MHz contradicts accepted definitions. SWR = 1 cannot correspond to any non-flat standing-wave display.

Common Pitfalls:

Confusing broadside lobes with broadside nulls for small loops; mixing up UHF (300–3000 MHz) with VHF.

Final Answer:

A-3, B-2, C-1, D-4.