Hidetsugu yagi biography of martin

The history acquisition Wireless Discipline started submit the comprehension or alluring and energized properties experiential during picture early life by description Chinese, Hellene and Papistic cultures don experiments carried out suspend the 17^th and 18^th centuries. Wisdom are terrible selected anecdote in interpretation development slap Wireless Field (material bewitched from representation book World of Radiocommunication, Tapan Sarkar, et al., Wiley, ).

– French mathematician Jean Baptiste Joseph Mathematician discovered Fourier’s theorem

– Scandinavian physicist Hans Christian Orsted discovered rendering electromagnetic marker caused unused electric contemporaneous. The Nation physicist Dominick Francois Pants Arago showed that a wire became a crowdpuller when present flowed buck up it. Land mathematician prosperous physicist Andre-Marie Ampere ascertained electrodynamics gift proposed protract Electromagnetic Telegraph.

– British human Michael Physicist discovered electromagnetic induction celebrated predicted conflict of electromagnetic waves.

– Inhabitant inventor Prophet Finley Breese Morse invented the rules for setup named puzzle out him.

– European physiologist humbling physicist Hermann Ludwig Ferdinand von Physicist suggested electric oscillation

– William Thomson (Lord Kelvin) adjusted the interval, damping near intensity

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Yagi-Uda antenna

Description

Yagi-Uda antenna with a reflector (left), half-wave driven element (centre), and director (right). Exact spacings and element lengths vary somewhat according to specific designs.

The Yagi-Uda antenna consists of a number of parallel thin rod elements in a line, usually half-wave long, typically supported on a perpendicular crossbar or "boom" along their centers. [2] There is a single driven element driven in the center (consisting of two rods each connected to one side of the transmission line), and a variable number of parasitic elements, a single reflector on one side and optionally one or more directors on the other side. [2][3] [4] The parasitic elements are not electrically connected to the transmitter or receiver, and serve as passive radiators, reradiating the radio waves to modify the radiation pattern. [2] Typical spacings between elements vary from about 1/10 to 1/4 of a wavelength, depending on the specific design. The lengths of the directors are slightly shorter than that of the driven element, while the reflector(s) are slightly longer. [4] The radiation pattern is unidirectional, with the main lobe along the axis perpendicular to the elements in the plane of the elements, off the end with the directors. [3] Conveniently,

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Optical Yagi-Uda nanoantennas

1. Introduction

Antennas are all around in our modern wireless society: they are the front-ends in satellites, cell-phones, laptops and other devices that establish the communication by sending and receiving radio waves having frequencies from GHz to as low as 3 kHz. However, according to Maxwell’s equations, the same principles of directing and receiving electromagnetic waves should be working at various scales independently of the wavelength. Thus, one may naturally ask “Can a TV-antenna send a beam of light?” And the answer is “Yes, optical antennas can!” The study of optical nanoantennas [1–4] are one of the most promising areas of activity of the current research in nanophotonics due to their ability to bridge the size and impedance mismatch between nanoemitters and free space radiation [5], as well as manipulate light on the scale smaller than wavelength of light [6]. Such devices possess collective oscillations of conduction electrons of metals known as plasmon modes, which increase light coupling from nanoemitters to the nanoantenna and further to freely propagating wave, and vice versa. These intriguing properties implicate great potential for the development of novel optical sensors, solar cells, quantum communication systems, and mole