directional antenna
Học thuậtThân thiện
Definition
- Noun:
- A type of antenna designed to transmit or receive radio signals primarily in one specific direction or within a narrow angular range: A directional antenna concentrates its signal power in a focused beam, rather than radiating equally in all directions. This allows for stronger signal strength and reduced interference from other directions compared to an omnidirectional antenna.
Examples of Usage
- Noun:
- The radio station installed a new directional antenna to improve its broadcast coverage to the north.
- For long-distance Wi-Fi links, a directional antenna is essential to establish a stable connection.
- The satellite dish is a common example of a parabolic directional antenna used for television reception.
Advanced Usage
"highly directional antenna": An antenna with a very narrow beamwidth, offering precise signal targeting.
- The military uses highly directional antennas for secure, point-to-point communication.
"directional antenna array": A system of multiple antenna elements arranged to create a directional radiation pattern.
- The cellular tower uses a directional antenna array to serve specific sectors of the city.
Variants and Related Words
- Antenna (n): A general device for transmitting or receiving radio waves.
- Omnidirectional antenna (n): An antenna that radiates or receives signals equally in all horizontal directions.
- Beamwidth (n): The angular width of the main lobe of a directional antenna's radiation pattern.
- Gain (n): A measure of an antenna's ability to direct radio frequency energy in a particular direction.
Synonyms
- Beam antenna: An antenna that projects a focused beam of radio waves.
- Yagi antenna: A specific, common type of directional antenna with multiple parallel elements.
Related Phrases
To point a directional antenna: To physically aim the antenna towards a specific signal source or target area.
- You must accurately point the directional antenna at the transmitter for the best signal.
Front-to-back ratio: A performance parameter for directional antennas, comparing the signal strength in the desired forward direction to that from the rear.
- A good directional antenna has a high front-to-back ratio to reject interference from behind.
Noun
- an antenna that transmits or receives signals only in a narrow angle