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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 directivity is the ratio of maximum radiation intensity (power per unit surface) radiated by the antenna in the maximum direction divided by the intensity radiated by a hypothetical isotropic antenna radiating the same total power as that antenna. For example, a hypothetical antenna which had a radiated pattern of a hemisphere (1/2 ...
Antennas can be classified in various ways, and various writers organize the different aspects of antennas with different priorities, depending on whether their text is most focused on specific frequency bands; or antenna size, construction, and placement feasibility; or explicating principles of radio theory and engineering that underlie ...
A patch antenna is a type of antenna with a low profile, usually consisting of a printed circuit board. It consists of a planar rectangular or circular sheet or "patch" of metal, mounted over a larger sheet of metal called a ground plane. It is the original type of microstrip antenna described by Howell in 1972. [1]
An antenna array (or array antenna) is a set of multiple connected antennas which work together as a single antenna, to transmit or receive radio waves. [ 1 ] : p.149 [ 2 ] The individual antennas (called elements ) are usually connected to a single receiver or transmitter by feedlines that feed the power to the elements in a specific phase ...
Outdoor antennas provide up to a 15 dB gain in signal strength and 15-20 dB greater rejection of ghost signals in analog TV. [6] Combined with a signal increase of 14 dB due to height and 11 dB due to lack of attenuating building walls, an outdoor antenna can result in a signal strength increase of up to 40 dB at the TV receiver. [6]
The radiation pattern of an antenna is a plot of the relative field strength of the radio waves emitted by the antenna at different angles in the far field. It is typically represented by a three-dimensional graph, or polar plots of the horizontal and vertical cross sections.
For such an antenna, the near field is the region within a radius r ≪ λ, while the far-field is the region for which r ≫ 2 λ. The transition zone is the region between r = λ and r = 2 λ . The length of the antenna, D, is not important, and the approximation is the same for all shorter antennas (sometimes idealized as so-called point ...