traveling-wave antenna
71Media and Publishing — ▪ 2007 Introduction The Frankfurt Book Fair enjoyed a record number of exhibitors, and the distribution of free newspapers surged. TV broadcasters experimented with ways of engaging their audience via the Internet; mobile TV grew; magazine… …
72General relativity — For a generally accessible and less technical introduction to the topic, see Introduction to general relativity. General relativity Introduction Mathematical formulation Resources …
73Negative index metamaterials — A negative index metamaterial causes light to refract, or bend, differently than in more common positive refractive index materials. Negative index metamaterials or negative index materials (NIM) are artificial structures where the refractive… …
74Parabolic reflector — Parallel waves coming in to a parabolic mirror are focused at a point F A parabolic reflector (or dish or mirror) is a reflective device used to collect or project energy such as light, sound, or radio waves. Its shape is that of a circular… …
75Line-of-sight propagation — refers to electro magnetic radiation including light emissions traveling in a straight line. The rays or waves are diffracted, refracted, reflected, or absorbed by atmosphere and obstructions with material and generally cannot travel over the… …
76Moving target indication — (MTI) is a mode of operation of a radar to discriminate a target against clutter. [1] In contrast to another mode, stationary target indication, it takes an advantage of the fact that the target moves with respect to stationary clutter. The most… …
77computer — computerlike, adj. /keuhm pyooh teuhr/, n. 1. Also called processor. an electronic device designed to accept data, perform prescribed mathematical and logical operations at high speed, and display the results of these operations. Cf. analog… …
78VHF omnidirectional range — This article is about the radio navigation aid. For other uses, see Vor. D VOR (Doppler VOR) ground station, co located with DME …
79Field (physics) — The magnitude of an electric field surrounding two equally charged (repelling) particles. Brighter areas have a greater magnitude. The direction of the field is not visible …
80rocket and missile system — ▪ weapons system Introduction any of a variety of weapons systems that deliver explosive warheads to their targets by means of rocket propulsion. Rocket is a general term used broadly to describe a variety of jet propelled missiles… …
