# Creacion de antena wifi

Páginas: 3 (725 palabras) Publicado: 1 de octubre de 2010

Hybrid-Douple-Quad-Array antennas are easy to build and offer high performance on gain. In principle they may be adapted to any frequency but due to dimensionsprefered application is UHF

The goal of this article is to show how construction can be made easy using cheap material like cables and pvc-pipes applied for electrical houseinstallations available at any homestore. Reflectors work fine with any kind of metal plates or pcb. The electrical impedance of a single double-quad-element varies with diameter of element wire and withdistance to reflector plate. So you also may succeed with standard 75 Ohms coax cables. The proof of the pudding is in the eating ! But watch velocity factor v. Electromagnetic waves run on light speed invaccuum and free air only. Moving in dielectricas like isolation material in coax cables slows down speed and shortens the wavelength λ (greek: lambda). This effect will be taken in consideration bymultiplying light speed c with velocity factor v. Figures on page 2 to 4 offer general hints for construction. For bending double quad elements you may use a pair of flat nose pliers. But bending ismore convenient when using a self made gauge. For construction of the slot milling tools should be available. When applying hard wood or plastic material even a regular circular saw will do it. Onsheets 5, 6 and 7 you'll find detailed dimensions for building a 13cm and a 23cm antenna fine for ATV,FM,SSB,Packet or WLAN. PS: The author welcomes any feedback working with antenna. Please mail yourpersonal experience to: weber.reinhardt@t-online.de

>= 1.7 λ
Gain
approx.

λ/ 4

15dBD / 17dBi
vertical

0.40λ

Polarisation

0.45λ

horizontal

>=1.5 λ

Reflector (Metal Plate)

50Ω

d

50Ω d

l
4x Coax 50 Ohms

Wavelenght

50Ω

50Ω

l = n*v*λ /2
[ n =1,2,3..]

λ= c/f
c = 2.99*10 m/s
8

25Ω 50Ω

100Ω
2x Coax 50...

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