Download Citation on ResearchGate | On Nov 30, , Juan Carlos Gómez and others published Diseño de Antenas Yagi Uda Usando. Abstract— This paper presents a simple broad band printed Yagi Uda antenna IndexTerms—Printed YagiUda antenna, Reflectors, Directors, Driven element. Yagi-Udaantenna From Wikipedia, the free encyclopedia Drawing of Yagi-Uda VHF television antenna from , used for analog channels.
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Thus the antenna radiates a unidirectional beam of radio waves from the front director end of the antenna. John Wiley and Sons. Thus the directivity of the array indeed is in the direction towards the director.
The element to the left of the feed element anteenas Figure 1 is the reflector. The Yagi-Uda antenna or Yagi Antenna is one of the most brilliant antenna designs.
Online Calculator Yagi Uda Antenna
A picture of Professor Yagi with a Yagi-Uda antenna is shown below. The rest of the elements are parasitic – they reflect or help to transmit the energy in a particular direction. You are probably familiar with this antenna, as they sit on top of roofs everywhere. 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.
Now the difficult computation is in determining that mutual impedance Z 21 which requires a numerical solution. We model element number j as having a feedpoint at the centre with a voltage V j and a current I j flowing into it. This so-called trap has the effect of truncating the element at the higher frequency band, making it approximately a half wavelength in length.
The Yagi-Uda Antenna – Yagi Antennas
The net effect of these two waves, when added bottom, leftis almost complete cancellation. With only the driven element present the driving point impedance would have simply been Z 11but has now been modified by the presence of the parasitic element.
Directive Short Wave Antenna, “. So one could as well model the operation of the parasitic element as the superposition of a dipole element receiving power and sending it down a transmission line to a matched load, and a transmitter sending the same amount of power up the transmission line back toward the antenna element. This will cause a phase distribution to occur across the elements, simulating the phase progression of a plane wave across the array of elements.
In other words, the crest of the forward wave from the reflector element antenaz the driven element just as the crest of the wave is emitted from that element. Retrieved 4 July Retrieved 11 September Similarly, the gain for this Antenaa antenna can be plotted as a function of director spacings, or as a function of the number of directors used.
The antenna was invented in by Shintaro Uda of Tohoku Imperial UniversityJapan with a lesser role played by his colleague Hidetsugu Yagi.
TV antennas are still a major application of the Yagi antenna. Yagi antenna design is done most often via measurements, and sometimes computer simulations. Radio frequency antenna types Antennas radio Radio electronics Japanese inventions Amateur radio. Let the driven element be designated 1 so that V 1 and I 1 are the voltage and current supplied by the transmitter.
Views Read Edit View history. This was the preface and notice in advance for a series of 11 papers with the same title by Uda between — on the antenna. At other angles, the power emitted is intermediate between the two extremes.
The above description is the basic idea of what is going on with the Yagi-Uda antenna. Secondly, if the reflector is longer than its resonant length, the impedance of the reflector will be inductive.
This feed antenna is often altered in yabi-uda to make it resonant in the presence of the parasitic elements typically, 0. The wave green from the driven element excites a current in the passive director which reradiates a wave blue having a particular phase shift see explanation in text.
Retrieved 29 July Modern Dictionary of Electronics 7 ed. Yagi demonstrated a proof of conceptbut the engineering problems proved to be more onerous than conventional systems.