“antenna”的概念、定义、翻译、参考文献-科学参考

antenna

Physics

See aerial.

Astronomy

A device used in radio astronomy to detect radio waves; also known as an aerial. In an antenna, radio waves induce an oscillating electric current in a conductor. The simplest antenna is a dipole antenna, which is a simple metal rod. More complex antennas, such as the Yagi antenna, may consist of a dipole or folded dipole (the driven element) with other conducting rods (parasitic elements) which direct or reflect the waves on to the dipole and so increase the antenna’s directivity and gain. The most powerful radio telescopes, especially at high frequencies, use parabolic (dish) antennas to collect waves and bring them to a focus. Large numbers of antennas may be combined in an array to achieve high resolution. Antennas may also be used to transmit radio waves.

Science and Technology

1. (aerial) A device that converts electric power into electromagnetic (radio or TV) waves, and vice versa. It is usually linked to a transmitter or receiver.
2. One of one or more pairs of sensory structures borne on the heads of arthropods.
3. One of a pair of colliding galaxies in the constellation Corvus.
Mike Allaby

Electronics and Electrical Engineering

The part of a radio system that radiates energy into space (transmitting antenna) or receives energy from space (receiving antenna). An antenna together with its feeders and all its supports is known as an antenna system. There is a great variety of specially designed antennas, most of which are described by their shape, e.g. umbrella, clover leaf, H. L. T, cigar, and corner antennas. The most important types of antennas are dipoles and directional antennas. See also Yagi antenna.

Biology

A long whiplike jointed mobile paired appendage on the head of many arthropods, usually concerned with the senses of smell, touch, etc. (see sensillum). In insects, millipedes, and centipedes they are the first pair of head appendages and are specialized and modified in many insects. In crustaceans they are the second pair of head appendages, the first pair (the antennules) having the sensory function, while the antennae are modified for swimming and for attachment.

单词	antenna
释义	antenna Physics See aerial. Astronomy A device used in radio astronomy to detect radio waves; also known as an aerial. In an antenna, radio waves induce an oscillating electric current in a conductor. The simplest antenna is a dipole antenna, which is a simple metal rod. More complex antennas, such as the Yagi antenna, may consist of a dipole or folded dipole (the driven element) with other conducting rods (parasitic elements) which direct or reflect the waves on to the dipole and so increase the antenna’s directivity and gain. The most powerful radio telescopes, especially at high frequencies, use parabolic (dish) antennas to collect waves and bring them to a focus. Large numbers of antennas may be combined in an array to achieve high resolution. Antennas may also be used to transmit radio waves. Science and Technology 1. (aerial) A device that converts electric power into electromagnetic (radio or TV) waves, and vice versa. It is usually linked to a transmitter or receiver. 2. One of one or more pairs of sensory structures borne on the heads of arthropods. 3. One of a pair of colliding galaxies in the constellation Corvus. Mike Allaby Electronics and Electrical Engineering The part of a radio system that radiates energy into space (transmitting antenna) or receives energy from space (receiving antenna). An antenna together with its feeders and all its supports is known as an antenna system. There is a great variety of specially designed antennas, most of which are described by their shape, e.g. umbrella, clover leaf, H. L. T, cigar, and corner antennas. The most important types of antennas are dipoles and directional antennas. See also Yagi antenna. Biology A long whiplike jointed mobile paired appendage on the head of many arthropods, usually concerned with the senses of smell, touch, etc. (see sensillum). In insects, millipedes, and centipedes they are the first pair of head appendages and are specialized and modified in many insects. In crustaceans they are the second pair of head appendages, the first pair (the antennules) having the sensory function, while the antennae are modified for swimming and for attachment.
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