Take a look at my tutorial for describing antennas for wlan deployment. Simulation of wire antennas with nec nec numerical electric code is a simulation method for wire antennas developed by the. Far field pattern for different antenna heights 31 10. What these numbers have in common is the belief that the feedpoint is the 300ohm point along the antenna element. An antenna described to nec is given in two parts, a structure and a sequence of controls. Nov 01, 2015 4nec2 antenna modeling of near field antenna interaction scenario based on video by michael pfeiffer no7on s. Multiple patterns can be superimposed on a single graph for comparison. Massiveelement antenna array the heat dissipation effect of the antenna is improved by expanding the metallic surface area of the antenna elements, which increases the share of the total area that is composed of metal. Nec code and experiments in the rf laboratory were used for this airspaced patch antenna study. Therefore, a countless variety of antennas can be used, and they are applicationspecific. Nec visualization, optimization and sweeping tool the 4nec2 tool is a windows and nec2 or nec4 based tool for both the starting and experienced antenna modeler that can be used to create, view and check your antenna geometry structure and generate, display and compare near and farfield radiation patterns. Listed under the software antenna analysis category that is. Numerical electromagnetics code nec2 unofficial home page.
Antenna characteristics page 3 a 3d power pattern b 2d power pattern in rectilinear format figure 5. Press f4 to bring up the radiation pattern display on the polar plot. A beginners tutorial for 4nec, a nec2 distribution written and tested by. The basic devices for modeling structures with the nec code are short, straight segments for modeling wires and flat patches for modeling surfaces. Index terms supernec software, helix antenna, radiation resistance. It also has a wide angle of beam in its radiation pattern. There is a wide and varied market of applications that embed the nec2 code within. An antenna radiation pattern or antenna pattern is defined as a mathematical function or a graphical representation of the radiation properties of the antenna as a function of space coordinates.
This is a 3 rd party book and is not connected to arie in any way. Antenna simulations with 4nec2 including an application. The package is intended to provide windows which show both antenna patterns and antenna configuration. Defaults the user only needs the intended operating frequency here. So by rotating the antenna, we can obtain cuts of the radiation pattern for instance the eplane cut or the hplane cut. Super nec has a number of builtin antennas that can be very easily constructed. The fields are linearly polarized, and in the horizontal direction when viewing the microstrip antenna as in figure 1a well see why in the next section. The nec ground plane gn card is always at the origin z 0. Rotate the antenna display and zoom in for details. This flat patch antenna series includes many connector options including n male, nfemale, sma, tnc, and mccard.
Typical gain of a patch antenna will be greater than 1. Introduction the starting point for this tutorial is the helix antenna. Radiation is the term used to represent the emission or reception of wave front at the antenna, specifying its strength. The results obtain that microstrip patch antenna can be used as client antenna in computer and workable antenna for wireless fidelity.
Nec structures are built up of elements such as straight wires, small surface patches, or helices. Correction and editing of nec 2 input code is allowed using most of cards from input nec 2 language. If the antenna had a 100% radiation efficiency, all directivity would be converted to gain. Supernec model structure of investigated patch antennas. The paper presents a broadband microstrip patch antenna for wireless. Nec 2 does not allow to model underground wires ref. This paper presents design and simulation of a rectangular micro strip patch array antenna at 2. The nec files may be used with any of the nec 2 or nec 4 programs such as 4nec2, gnec or cocoanec, however some of them with tapered elements may only be simulated accurately by nec 4. Antenna modeling files american radio relay league. Apr 12, 2014 this is a three dimensional plot of the current distribution and radiation pattern of a horizontallypolarized 5element cubical quad antenna for 432 mhz at 1.
To be used with either nec4 or yagi optimizer modeling programs. Yagio is similar to lpcad, it uses keyboard commands instead of a mouse menu. Richards, theory and experiment on microstrip antennas, ieee trans. Well model a vertical monopole like a whip antenna on an old radio. A circular microstrip patch antenna is designed to operate at 2. The basics of patch antennas, updated orban microwave. These flat patch antennas provide 8 dbi of gain and a durable uvstable, ul flame rated radome that can be painted. Antenna patterns and their meaning much can be learned about how an antenna performs from its patterns. Mom solution of hallens or pocklingtons integral equations. Yag files can be converted using the msdos based scale.
The code was made publicly available for general use and has subsequently been distributed for many computer platforms from mainframes to pcs. Antenna simulations with 4nec2 including an application example for 2300mhz presentation made by gunthard kraus, dg8gb, at the radio amateur meeting at munich 1032018 1. Analysis of an airspaced patch antenna near 1800 mhz hermine n. To switch between a vertical and horizontal plane view, select far field horizontal plane or press the spacebar. Also in nec 2 for mmana it is possible to make calculation in a case when some wires in mmana model are in dielectric isolation. This rectangular microstrip patch antenna is designed for wireless communication application that works at 2. Yagio runs under windows 2000, xp, vista, win 7 and likely win 8. Antenna simulations with 4nec2 including an application example. In this case the model is very simple, a single vertical wire. These results show that a microstrip patch antenna mainly radiates in the vertical direction. Technical reports from the electronics group at the. Antenna analysis program for windows and macintosh computers. This is in agreement with the theoretical radiation pattern.
However to use it for amateur radio antenna modelling is not that hard. Details on how to construct this antenna, both as standalone and as a parabolic dish feed can be found at this link. An nec2 compatible numerical electromagnetics code by. Lcoms hg2409p high performance directional flat patch antenna series are suitable for indoor and outdoor applications in the 2. Figure 2 present the simulated 2d cut view and 3d far zone eplane radiation patterns for this antenna. The fundamentals of patch antenna design and performance. In any illustration, the sketch drawn to represent the radiation of an antenna is its radiation pattern.
On this page you can see a 2d representation of the radiation pattern of your antenna. There are several different types and they all have their place. View antenna display, showing the wires making up the model of the fiveelement beam, with currents and 2d slice superimposed to show orientation. Nec visualization, optimization and sweeping tool the 4nec2 tool is a windows and nec 2 or nec 4 based tool for both the starting and experienced antenna modeler that can be used to create, view and check your antenna geometry structure and generate, display and compare near and farfield radiation patterns. Therefore, nec has used antennas with a splitring structure note 1, to achieve about half the size of a general patch antenna. Antenna descriptions and pattern plots are easily saved and recalled for future analysis. An accompanying article in both latex and postscript form describes the process of designing a simple antenna using the system. An antenna and any other conducting objects in its vicinity that affect its performance must be modeled with strings of segments following the paths of wires and with patches covering surfaces.
The size of the radiation pattern can be adjusted with the. The user interface, graphical editing features, and data display capabilities allow analysis of antenna patterns, of near, far, and groundwave fields, as well as currents and charge densities. Basic patch antenna design although there are many variations on patch antenna design, the basic configuration is shown in figure 1, where l is then length relative to the feedpoint and w is the width. Next well consider more aspects involved in patch microstrip antennas.
Introduction a major component of a wireless lan system is the antenna. Wire monopole this consists of a simple wire soldered at one end from which it is fed. A major limitation for the performance of the patch antenna is the dielectric substrate. To install the 4nec2 package, follow the below steps. The numerical electromagnetics code, or nec, is a popular antenna modeling system for wire. The antenna is claimed to provide a good match under these conditions to coax on the fundamental and most even harmonics.
Nec 4 further allows electrically small antennas to be modeled with better accuracy. These antennas can be mounted on the surface of highperformance aircraft, spacecraft, satellites, missiles, cars, and even handheld mobile telephones. Therefore for training a simple 6 turns antenna is calculated, see fig 1. Power patterns for an arbitrary antenna 2 the maximum sidelobe level sll is often of concern to antenna designers, particularly if the antenna was designed to focus power in a speci c direction, since sidelobes essentially represent a. With a patch antenna, varying the height by only one millimeter, has a large effect on the pattern. Especially designed for antenna modelers, 4nec2 is a simple tool for designing, optimizing and verifying 2d or 3d geometry structures. Hfsss microstrip patch antenna design part1basics of antenna design using hfss software. May 03, 2015 a simple antenna nec2 was based on punch cards and an antenna model was described as a series of cards. Read 36947 times 0 members and 1 guest are viewing this topic. The nec engine provides support for modeling patch antennas as well.
This is in agreement with the theoretical radiation pattern for these structures. This radiation pattern shows that the antenna radiates more power in a certain direction than another direction. Optimizing the antenna length thick wire dipole of chapter 7 27 9. Normalized radiation pattern for microstrip patch antenna. How to produce a nec antenna file and what software to. Typical half wave patches have efficiencies well above 90%. The numerical electromagnetics code, or nec, is a popular antenna modeling system for wire and surface antennas.
If you model the patch as a grid of wires, then changing the height above this ground is a very laborious job. Click the run nec button in the upper right hand corner of the 4nec2 edit window. It also includes stateoftheart 3d visualization and a drawing style structure editor. Take into account that nec 2 computes the total current in the antenna, without making differences between common mode currents and differential mode currents ref. Page 2 arrl pacificon 2004 october 15, 2004 outline electromagnetics and antenna engineering basics dipole impedance by antenna theory. Find the range where the radiation pattern looks pleasing with a well defined rounded main lobe and the gain is reasonable and go for the middle. Several other items, such as currents and wire numbers, can be. See the pattern and antenna currents on the same color 3d display as the antenna. The following files and links point to nec aoyo models of various ham antennas that i have simulated andor tested over the past 30 years as an antenna designer. An 80meter antenna would thus match well on 40, 20, and 10, while a 40meter antenna would match well on 20 and 10 meters. Design and implementation of patch antenna 5 designs, and very versatile in terms of resonant frequency, polarization, pattern, and impedance.
Fundamental specifications of patch antennas radiation pattern a patch antenna radiates power in certain directions and we say that the antenna has directivity usually expressed in dbi. A great circle cut is when 0 and is allowed to vary from 0. It consists of a flat rectangular sheet or patch of metal, mounted over a larger sheet of metal called a ground plane. The basic principles are illustrated here for a rectangular patch, but the principles apply similarly for other patch shapes. In figure 2, the positioning system rotating the antenna such that it faces the source of illumination.
The directivity of patch antennas is approximately 57 db. A novel technique for enhancing bandwidth and gain of microstrip patch antenna is successfully designed in this pa per. A maximum quantity of processable segments 3000, nec 2 engine compiled by arie from neede, netherlands. Nec develops antenna heat dissipation technology enabling. This section investigates simulation of the rectangular probefed. Thanks for downloading and reading this definitive guide to the widely popular 4nec2 antenna modeling software. Radiation pattern the patchs radiation at the fringing fields results in a certain far field radiation pattern. This paper describes many of the common antenna parameters that can be understood from the patterns. If it is not visible just press f3, or if the window is visible and the geometry was not updated just select viewreset on the geometry window. We use the cavity model to explain the operation of the patch antenna. Antenna solver is a product of grating solver development co. The standard is nec2 there are many software applicati ons, even free ones.
The proposed microstrip patch antenna achieves a fractional bandwidth of 21. Furthermore, the additional metal plates employ a frequencyselective surface fss structure, making them. Analysis of an airspaced patch antenna near 1800 mhz. There is also a sample nec model that you can use to test your setup. Major additions in nec 2 are the numerical greens function for partitionedmatrix solution and a treatment for lossy grounds that is accurate for antennas very close to the ground surface. The following listing shows an nec input file that requests a radiation pattern from a vertical. Super numerical electromagnetic code snec software and. The arrl antenna book uses the formula carr gives the figure as 0.
What do hobbyists use if they have a desireneed to simulate a pcb antenna. The 4nec2 tool is a windows and nec2 or nec4 based tool for both the starting and. In this case, the received power comes from direction. Jul 25, 2018 with a patch antenna, varying the height by only one millimeter, has a large effect on the pattern. Input impedance for different antenna heights 29 9. Marquette university, 2011 microstrip antennas are a type of printed antenna which consists of a patch on top of a grounded substrate. One can simply understand the function and directivity of an antenna by having a look at its radiation pattern. Moreover, by holding them in an upright position and arranging them like checkered plates, nec has formed flow paths for the air containing heat and realized heat dissipation from the antenna surface.
Nec 2 retains all features of the earlier version nec 1 except for a restart option. Antenna modeling files introduction in january, 1998, the arrl board of directors changed the arrl advertisementacceptance policy to permit the advertising of antenna gain figures for antennas whose performance can be accurately modeled using either nec 4 or yagi optimizer modeling programs. A more recent version of the antenna cut for 40 meters uses a different ratio. Nec tutorial basic introduction nec can seem a bit imposing at first glance, with its manuals dating back to the good old days of fortran iv and punched cards.
56 1225 982 1090 1395 491 1325 528 18 832 223 1179 1445 455 826 189 838 1290 93 1164 1355 622 1323 1376 165 671 1319 9 1162 1429 1402 1473 1263 470 1152 1117