Name a type of semi-directional antenna.

Name a type of semi-directional antenna.

• A. Bi-directional, Yagi, or inverted V antenna.
• B. Parabolic dish.
• C. Omnidirectional vertical.
• D. Loop antenna.

Answer: (A)

Semi-directional antennas are designed to concentrate most of their radiated (or received) energy in specific directions, giving a moderate beam with higher gain than an omnidirectional radiator but not the extremely narrow beam of a dish. A bi-directional pattern, like a straight or folded dipole, produces two main lobes opposite each other and is a classic example of semi-directional behavior. A Yagi-Uda array uses multiple elements with a reflector and directors to create a strong forward lobe, providing notable gain in one direction while still not being as narrowly focused as a parabolic dish. An inverted-V, essentially a folded or bent dipole, concentrates energy along the axis of the V, giving directional gain as well. In contrast, a parabolic dish creates a very narrow, highly directional beam; an omnidirectional vertical radiates with little or no directional preference in the horizontal plane; and a loop antenna has a different, often more complex directional pattern that isn’t typically categorized as semi-directional in basic classifications.

Semi-directional antennas are designed to concentrate most of their radiated (or received) energy in specific directions, giving a moderate beam with higher gain than an omnidirectional radiator but not the extremely narrow beam of a dish. A bi-directional pattern, like a straight or folded dipole, produces two main lobes opposite each other and is a classic example of semi-directional behavior. A Yagi-Uda array uses multiple elements with a reflector and directors to create a strong forward lobe, providing notable gain in one direction while still not being as narrowly focused as a parabolic dish. An inverted-V, essentially a folded or bent dipole, concentrates energy along the axis of the V, giving directional gain as well.

In contrast, a parabolic dish creates a very narrow, highly directional beam; an omnidirectional vertical radiates with little or no directional preference in the horizontal plane; and a loop antenna has a different, often more complex directional pattern that isn’t typically categorized as semi-directional in basic classifications.