Which term describes the energy focusing property of an antenna that concentrates radiated energy in a particular direction?

Which term describes the energy focusing property of an antenna that concentrates radiated energy in a particular direction?

• A. Gain/Directivity
• B. Bandwidth
• C. Impedance
• D. Power rating

Answer: (A)

Antennas shape their radiation pattern, so energy can be directed toward a specific direction. This focusing ability is described by directivity—the measure of how much more power is radiated in a chosen direction than by an ideal isotropic radiator that spreads energy equally in all directions. In real antennas, efficiency isn’t perfect, so the actual power directed in that direction is described by gain, which equals directivity times efficiency. In SATCOM terms, higher directivity/gain means more of the transmitter’s power is focused toward the satellite, improving the link performance. Bandwidth describes the range of frequencies the antenna works well at, impedance is the feed point’s voltage–current relationship for matching, and power rating is the maximum safe power the antenna can handle.

Antennas shape their radiation pattern, so energy can be directed toward a specific direction. This focusing ability is described by directivity—the measure of how much more power is radiated in a chosen direction than by an ideal isotropic radiator that spreads energy equally in all directions. In real antennas, efficiency isn’t perfect, so the actual power directed in that direction is described by gain, which equals directivity times efficiency. In SATCOM terms, higher directivity/gain means more of the transmitter’s power is focused toward the satellite, improving the link performance.

Bandwidth describes the range of frequencies the antenna works well at, impedance is the feed point’s voltage–current relationship for matching, and power rating is the maximum safe power the antenna can handle.