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Antennae (sg.: antenna) (sometimes referred to as "feelers") are paired appendages used for sensing in arthropods. Antennae are connected to the first one or two segments of the arthropod head. They vary widely in form but are always made of one or more jointed segments.
In botany, "seta" refers to the stalk supporting the capsule of a moss or liverwort (both closely related in a clade called "Setaphyta"), and supplying it with nutrients. The seta is part of the sporophyte and has a short foot embedded in the gametophyte on which it is parasitic.
A transmitarray antenna (or just transmitarray or called as layered lens antenna [2]) is a phase-shifting surface (PSS), a structure capable of focusing electromagnetic radiation from a source antenna to produce a high-gain beam. [3] Transmitarrays consist of an array of unit cells placed above a source (feeding) antenna. [4]
A microstrip antenna array for a satellite television receiver Diagram of the feed structure of a microstrip antenna array. In telecommunication, a microstrip antenna (also known as a printed antenna) usually is an antenna fabricated using photolithographic techniques on a printed circuit board (PCB). [1] It is a kind of internal antenna.
Antenna designs incorporating metamaterials can step-up the antenna's radiated power. Conventional antennas that are very small compared to the wavelength reflect most of the signal back to the source. A metamaterial antenna behaves as if it were much larger than its actual size, because its novel structure stores and re-radiates energy.
Typical GSM sector antenna outdoor unit. A sector antenna is a type of directional microwave antenna with a sector-shaped radiation pattern.The word "sector" is used in the geometric sense; some portion of the circumference of a circle measured in degrees of arc. 60°, 90° and 120° designs are typical, often with a few degrees 'extra' to ensure overlap and mounted in multiples when wider or ...
The first modern horn antenna in 1938 with inventor Wilmer L. Barrow. A horn antenna or microwave horn is an antenna that consists of a flaring metal waveguide shaped like a horn to direct radio waves in a beam. Horns are widely used as antennas at UHF and microwave frequencies, above 300 MHz. [1]
Such fractal antennas are also referred to as multilevel and space filling curves, but the key aspect lies in their repetition of a motif over two or more scale sizes, [3] or "iterations". For this reason, fractal antennas are very compact, multiband or wideband, and have useful applications in cellular telephone and microwave communications.