Subelement E: Antenna Systems- 5 Key Topics – 5 Exam Questions— Topic 39: Antenna Systems
Question 8-39E5
Element 8 (RADAR)How does antenna length affect the horizontal beamwidth of the transmitted signal?
Explanation
Longer antennas, particularly those designed for directionality, generally exhibit higher gain. This increased gain is achieved by concentrating the transmitted radio frequency energy into a more focused radiation pattern. Think of it like focusing a flashlight beam: a more powerful lens (analogous to a longer, more directive antenna) creates a tighter, brighter spot.
Therefore, a longer antenna typically results in a narrower horizontal beamwidth. The energy is directed more precisely in a specific azimuthal direction rather than being spread out broadly. This concentration of energy in a smaller angular sector is a fundamental characteristic of higher-gain antennas. Options A and C contradict this principle of antenna directivity and gain.
Related Questions
8-39E3 Good bearing resolution largely depends upon:8-39E4 The center of the transmitted lobe from a slotted waveguide array is:8-39E6 What is the most common type of RADAR antenna used aboard commercial maritime vessels?8-3A1 Frequencies generally used for marine RADAR are in the ___ part of the radio spectrum.8-3A2 Practical RADAR operation requires the use of microwave frequencies so that: