Antennas Information on GlobalSpec

Antennas are structures used to collect or radiate electromagnetic waves. Antennas can be considered specialized transducers that convert RF fields into AC line signals or vice versa. The two main types of antennas are the receiving antenna, which intercepts RF energy and delivers AC to electronic equipment, and the transmitting antenna, which is fed with AC from electronic equipment and generates an RF field.

At frequencies below 3 GHz, many different types of antennas are used such as simple monopole, dipoles, patches or arrays. Dish antennas are generally practical and commonly used at microwave frequencies (above approximately 3 GHz). In wireless data applications, satellite communications and other high bandwidth microwave applications, the most common type of antenna is the dish. Other commonly available antenna styles include omnidirectional, directional, arrays, microstrip, panel, and whips (monopoles).

Omnidirectional antennas radiate equal power in all directions in a horizontal plane. Conversely, directional antennas radiate their power in either one or two directions. These are referred to as uni- and bi-directional antennas, respectively.

Arrays are collections of antenna elements (dipoles, slot, loops, and microstrips) that work in concert. Two of the more common array styles are log periodic and Yagi-Uda. Log periodic arrays are multi-element, unidirectional, narrow-beam antennas that have impedance and radiation characteristics that are regularly repetitive as a logarithmic function of the excitation frequency. The length and spacing of the elements of a log periodic antennas increase logarithmically from one end to the other. Log periodic antennas are often used in broadband applications. Yagi-Uda arrays consist of three or more half-wave elements (one driven, one reflector, and one or more directors). Yagi antennas or Yagi-Uda arrays offer very high directivity and gain.

Microstrips are typically low efficiency short radiating/receiving antennas, popular for their low profile. Microstrips are easily fabricated with printed circuit board techniques and can be made to conform to most surface profiles. They can have an unlimited number of shapes and sizes. When built using special dielectric materials, smaller than natural antennas can be realized that will fit small packages

Panel or sector antennas have multiple antenna elements to radiate or collect signals from different sectors in a cell. A panel or sector panel antennas usually have a flat panel shape and are usually enclosed within a plastic radome to protect the elements and/or any electronics.

Whip antennas are flexible rod antennas, usually between 1/10 and 5/8 wavelength long, supported on a base insulator. These capacitive antennas or electric doublets are insulated from the structure (plane, car or other product) and the whole assembly radiates. The standard, wire monopole is probably the most widely used antenna on existing mobile telecommunication applications with the normal mode helix coming in a close second.

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Products & Services Related to Antennas

Access Points

Access points are transmitter / receivers (transceivers) that connect to a network through an interface such as a bus or connector. They receive, store, and transmit data between the wireless LAN and the wired structure.

Diplexers and Duplexers, RF

RF diplexers are three-port frequency-dependent devices that may be used as a separator or a combiner of signals. RF duplexers allow a transmitter operating on one frequency and a receiver operating on a different frequency to share a common antenna with a minimum of interaction and degradation of the different RF signals.

Horn Antennas

Horn antennas are used for the transmission and reception of microwave signals. They are usually fed by waveguides.

Navigational Instruments and Avionics

Navigational instruments and avionics include GPS devices, compasses, chronometers, radar units and other instruments for orientation, relative position and absolute position (longitude / latitude).

Radar Systems and Products

Radar systems and products have synchronized transmitters and receivers that send radio waves and detect their reflections from objects, surfaces or sub-surface structures.

RF Repeaters

RF repeaters have independent paths for reception and transmission, through which they collect and send signals to antennas and other stations.

RF Waveguide Components

RF waveguide components are circular, elliptical or rectangular metal tubes or pipes through which electromagnetic waves are propagated in microwave and RF communications. The wave passing through the medium is forced to follow the path determined by the physical structure of the guide.

Towers, Poles and Support Structures

Towers, poles and support structures elevate, support and/or position personnel and equipment such as antennas, lighting, surveillance cameras or sensors, wind turbines, weather instruments, and power lines.

Wireless Modems

Wireless modems transmit modulated data using electromagnetic waves.

Wireless Systems

Wireless systems consist of combined RF components such as transmitters, receivers, transceivers, filters, down / up converters, antennas and antenna positioners.

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