close frequency signals
21Filter design — is the process of designing a filter (in the sense in which the term is used in signal processing, statistics, and applied mathematics), often a linear shift invariant filter, which satisfies a set of requirements, some of which are contradictory …
22Heterodyne — This article is about waveform manipulation. For the use of the term in poetry, see Heterodyne (poetry). For the webcomic characters, see Girl Genius. Heterodyning is a radio signal processing technique invented in 1901 by Canadian inventor… …
23Invention of radio — Great Radio Controversy redirects here. For the album by the band Tesla, see The Great Radio Controversy. Contents 1 Physics of wireless signalling 2 Theory of electromagnetism …
24Metamaterial antenna — This Z antenna tested at the National Institute of Standards and Technology is smaller than a standard antenna with comparable properties. Its high efficiency is derived from the Z element inside the square that acts as a metamaterial, greatly… …
25Copper wire and cable — Copper has been used in electric wiring since the invention of the electromagnet and the telegraph in the 1820s.[1][2] The invention of the telephone in 1876 proved to be another early boon for copper wire.[3] Today, despite competition from… …
26Wardenclyffe Tower — (1901 ndash; 1917) also known as the Tesla Tower, was an early wireless telecommunications aerial tower designed by Nikola Tesla and intended for commercial trans Atlantic wireless telephony, broadcasting, and to demonstrate the transmission of… …
27Oscilloscope — This article is about current oscilloscopes, providing general information. For history of oscilloscopes, see Oscilloscope history. For detailed information about various types of oscilloscopes, see Oscilloscope types. Illustration showing the… …
28telecommunications media — Introduction equipment and systems metal wire, terrestrial and satellite radio, and optical fibre employed in the transmission of electromagnetic signals. Transmission media and the problem of signal degradation Every… …
29Power line communication — or power line carrier (PLC), also known as power line digital subscriber line (PDSL), mains communication, power line telecom (PLT), power line networking (PLN), or broadband over power lines (BPL) are systems for carrying data on a conductor… …
30Diplexer — A diplexer is a passive device that implements frequency domain multiplexing. Two ports (e.g., L and H) are multiplexed onto a third port (e.g., S). The signals on ports L and H occupy disjoint frequency bands. Consequently, the signals on L and… …
