Various radio communication antennas
Directional antenna: An antenna that propagates in a certain direction.
Non-directional antenna: An antenna that radiates or receives electromagnetic waves uniformly in all directions. It is called a non-directional antenna, such as a whip antenna for small communication devices.
Broadband antenna: An antenna whose directivity, impedance, and polarization characteristics remain almost unchanged over a wide band is called a broadband antenna.
Tuned antenna: An antenna with a predetermined directivity only in a very narrow frequency band, called a tuned antenna or a tuned directional antenna. In-phase horizontal antennas, folded antennas, and zigzag antennas are all tuned antennas.
Shortwave antenna: A transmitting or receiving antenna that works in the shortwave band, collectively referred to as shortwave antenna.
Shortwave is mainly propagated by sky waves reflected by the ionosphere, and is one of the important means of modern long-distance radio communication.
Ultrashort wave antenna: The transmitting and receiving antennas that work in the ultrashort wave band are called ultrashort wave antennas.
Microwave antennas: Transmitting or receiving antennas that work in meter waves, decimeter waves, centimeter waves, millimeter waves, etc., collectively referred to as microwave antennas. Microwaves mainly rely on space waves to propagate. In order to increase the communication distance, the antenna is set up relatively high.
Vertical antenna: A vertical antenna refers to an antenna placed perpendicular to the ground. It has two forms, symmetric and asymmetric, and the latter is widely used. Symmetrical vertical antennas are often center-fed. The asymmetric vertical antenna is fed between the bottom of the antenna and the ground, and its maximum radiation direction is concentrated in the ground direction when the height is less than 1/2 wavelength, so it is suitable for broadcasting. Asymmetric vertical antennas are also called vertical ground antennas.
Inverted L antenna: An antenna formed by connecting a vertical down conductor to one end of a single horizontal wire. Because its shape resembles the reverse of the English letter L, it is called an inverted L-shaped antenna. Inverted L antennas are generally used for long-wave communications. Its advantages are simple structure and convenient erection; its disadvantages are large floor area and poor durability.
T-shaped antenna: In the center of the horizontal wire, connect a vertical down conductor, the shape is like the English letter T, so it is called T-shaped antenna. It is the most common type of vertically grounded antenna. The horizontal part of the radiation is negligible, and the vertical part produces radiation. Generally used for long wave and medium wave communications.
Umbrella antenna: At the top of a single vertical wire, lead several inclined conductors in various directions. The antenna formed in this way is shaped like an open umbrella, so it is called an umbrella antenna. Features and uses are the same as the inverted L-shaped and T-shaped antennas.
Whip antenna: The whip antenna is a bendable vertical rod antenna whose length is generally 1/4 or 1/2 wavelength. Most whip antennas do not use ground wires but use ground nets. Small whip antennas often use the metal shell of a small radio as a ground net. The whip antenna can be used for small communication devices, walkie talkies, car radios, etc.
Symmetrical antenna: Two parts of the same length but the center is disconnected and connected to feed the wire, which can be used as a transmitting and receiving antenna. The antenna formed in this way is called a symmetrical antenna. Because antennas are sometimes called vibrators, symmetrical antennas are also called symmetrical vibrators, or dipole antennas. A symmetrical oscillator with a total length of half a wavelength is called a half-wave oscillator, also called a half-wave dipole antenna. It is the most basic unit antenna and is also the most widely used. Many complex antennas are composed of it. The half-wave vibrator has simple structure and convenient power feeding, and is widely used in short-distance communication.
Cage antenna: It is a wide-band weak directional antenna. It is suitable for short-distance trunk communication.
Angular antenna: It belongs to a type of symmetrical antenna, but its two arms are not arranged in a straight line, forming an angle of 90° or 120°, so it is called an angular antenna. This kind of antenna is generally installed horizontally, and its directivity is not significant. In order to obtain the wide-band characteristics, the double arms of the angular antenna can also adopt a cage structure, which is called an angular cage antenna.
Folded antenna: A symmetrical antenna that is bent into parallel with each other is called a folded antenna. The folded antenna is a tuned antenna with a narrow working frequency. It is widely used in shortwave and ultrashort wave bands.
Yagi antenna: also known as the steering antenna. The advantages of the Yagi antenna are simple structure, light weight and firmness, and convenient power feeding; the disadvantages are narrow frequency band and poor anti-interference. It is applied in ultrashort wave communication and radar.
Sector antenna: It has two forms: metal plate type and metal wire type. Sector antennas are used for ultrashort wave reception.
Biconical antenna: The biconical antenna consists of two cones with opposite cones. The biconical antenna is mainly used for ultrashort wave reception.
Parabolic antenna: The parabolic antenna is a directional microwave antenna, which is widely used in microwave relay communications, tropospheric scatter communications, radar and television.
V-shaped antenna: It is an antenna that is composed of two wires at an angle to each other and shaped like the English letter V.
Diamond antenna: It is a broadband antenna. Diamond antennas are generally used for large and medium-sized shortwave receiving stations.
Disk cone antenna: is a kind of ultrashort wave antenna.
Fishbone antenna: Fishbone antenna, also called side-fire antenna, is a special shortwave receiving antenna. Compared with the diamond antenna, the fishbone antenna has the advantages of small side lobes, small interaction between the antennas, and small footprint; the disadvantage is low efficiency, and the installation and use are more complicated.
Periscope antenna: In microwave relay communication, the antenna is often placed on a very high bracket, and is mainly used in microwave relay communication with small capacity.
Helical antenna: is an antenna with a spiral shape.
Horn parabolic antenna: The horn parabolic antenna consists of two parts, the horn and the parabola. Horn parabolic antennas are widely used in trunk relay communications.
Horn antenna: also known as horn antenna. The advantage is the bandwidth of the working frequency; the disadvantage is that it is larger, and for the same aperture, its directivity is not as sharp as a parabolic antenna.
Horn lens antenna: It is composed of a horn and a lens mounted on the horn diameter, so it is called a horn lens antenna. It is widely used in microwave trunk communication with a large number of channels.
Lens antenna: In the centimeter wave band, many optical principles can be used for antennas. Lens antennas are used in microwave relay communications.
Slotted antenna: Cut one or several narrow slots on a large metal plate and feed with coaxial lines or waveguides. The antenna formed in this way is called a slotted antenna, or a slot antenna. Especially suitable for use on high-speed aircraft. Its disadvantage is that it is difficult to tune.
Dielectric antenna: Dielectric antenna is a round rod made of low-loss and high-frequency dielectric material. The advantage of dielectric antenna is small size and sharp directivity; the disadvantage is that the medium is lossy, so the efficiency is not high.