Antenna fundamentals – Match each term to its correct definition List I (Term) A. Effective length of an antenna B. Capture area (effective aperture) C. Front-to-back ratio List II (Definition) Ratio of power (or field) radiated in the forward direction to that in the reverse direction Effective area that relates received power to incident power density Ratio of open-circuit induced voltage to the incident electric field (per unit E-field) Choose the correct mapping.

Introduction / Context:
Antenna performance is summarized by several canonical parameters. Correctly distinguishing effective length, effective aperture, and front-to-back ratio is essential when moving between transmit and receive viewpoints and when comparing directional patterns.

Given Data / Assumptions:

• Effective length converts an incident field to an open-circuit voltage.
• Capture area (effective aperture) converts incident power density to received power.
• Front-to-back ratio compares forward radiation to backward radiation.

Concept / Approach:

Match each term to its textbook definition. Effective length deals with induced voltage per field, capture area with power collection capability, and F/B ratio with directivity discrimination front vs. back lobes.

Step-by-Step Solution:

Verification / Alternative check:

These are the standard definitions used in antenna handbooks and are unit-consistent: length (meters), area (square meters), and dimensionless ratio (dB when expressed logarithmically).

Why Other Options Are Wrong:

Swapping 2 and 3 confuses receive voltage with received power concepts; assigning F/B to an area has no physical meaning.

Common Pitfalls:

Forgetting that effective length is strictly a receiving parameter linked to Voc, while effective aperture ties to received power and gain.

Final Answer:

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