Those field strength summations can be done by either graphical or mathematical integration. Many excellent examples of both graphical and mathematical methods appeared in literature printed prior to , for example, F. Terman, Radio Engineering , 2d ed, p. The MININEC moment method of far field radiation calculation is a mathematical integration method based in principle upon the fundamental concept of summing fields from many small elemental sections of thin antenna conductors that compose an antenna system.
Information about the moment method of far radiation field determination has appeared in Amateur Radio literature.
However, those two examples are written in Japanese and are believed to be available only in Japan. The mathematical calculations required to perform far radiation field integrations are complex and laborious to do manually, but MMANA uses an improved faster and requiring less memory MININEC computation engine to do the work for you.
You can simply describe an antenna, or load an antenna description file someone else has created, click a Start button, and MMANA will calculate and plot the vertical and horizontal far field radiation patterns of the antenna for you.
It also will calculate the feed impedance, feed-line SWR, bandwidth, and other things. Right click and hold on the end point and it is possible to move the wire to any position. Hold the shift key while holding the right click button to pull the wire vertically or horizontally.
By holding the control key and the right click button it is possible to alter the angle without changing the length of the wire.
Move the cursor to the middle of a wire, the cursor shape will change to an arrowhead with a square box, hold the right click button to move the wire to any required position. Holding the shift button at the same time will move the wire in a vertical or horizontal direction. To add a new wire, right click the New Wire button in the menu panel. Click on the position where the new line starts and drag the new wire to the required end point.
The actual length of the wire will be displayed in the Parameters window top right hand side of the screen. The length can then be adjusted by selecting Edit Wire. Alternatively the wire size can be directly input by clicking the right hand side Parameters menu window. Note that in the 3-D view window, you only can add a new wire that is connected to another existing wire. To Edit a wire, click the Edit Wire button in the menu panel, and click on the wire to be edited.
Press DELETE key to remove the wire, or click on an end of the wire and drag the wire to adjust the length to the required size. Alternatively right click to open the Editing pop-up window where the special functions can be accessed. Click and drag to place a new square loop. Note that this mode is not available in the 3-D view window. The editor is designed to simplify the input of data for complex antennas such as the 6 element Yagi or octagonal loop.
Use of the Geometry window to input such data can be very tedious and may result in simple errors when specifying the elements using the X-Y-Z coordinates. The Element Editor simplifies this operation by providing a format that is intuitive. Values for width, length, perimeter, and element spacing are entered in the Element Editor table shown above. These features are described in the following sections using a yagi antenna as an example. Initially, define one element length of a Yagi antenna.
Enter 1. The rest of the first line is populated automatically. A new pop-up window is displayed, select ADD to fill the second line.
This is useful for defining a complicated element e. To delete a line, place the cursor anywhere on the line, right click and select Del from the pop-up window. But, it will not re-number the source wire. Make sure that the source is placed on the correct wire - it may often be necessary to zoom in to accurately place or replace the source, especially if an antenna image has a large number of elements.
Move the cursor to the first cell of the Form column it should be displaying H Line and right or left click. The first line in the table will change. V Quad Vertical Quad. Vertical Quad appears in the Form column and the width changes to 0. Select View, the simple single line element is now a square. It may be necessary to zoom in as the these options are quite small. For practice try changing the first element to some of the other options e.
Place the cursor on the value that needs to be changed, and then hit backspace to clear the data area. Now type in the value required and hit return, the value will have changed. There are two radio buttons on the Element Table.
When Change only the end points is selected, only the position of the end points of a selected element, which can consist of two or more wires, will be changed. Select Change all coordinates proportionally all of the associated wires will be changed proportionally on the X, Y and Z axes.
The element having a branch toward X-axis e. For this reason, it is a good idea to extend the capacity hat symmetrically with respect to the element.
When the Check box at the bottom left is ticked the table will show the the spacing between the wire elements. When the check box is empty the table will show the distances from first wire element in the table.
When lambda is checked, the wire elements are measured in wavelengths, otherwise, the wire length is displayed in meters radius is in millimeters. Wires that have the same XYZ coordinates are assumed to be connected to each other. The program then analyzes each element's dimensions by looking at the vectors.
However, if, after optimizing an antenna, the results are quite different from the expected values, it may be necessary to change the order of element definitions by using the "Edit by text function" in the tool bar Edit menu. The tool is provided to simplify making changes to complex antennas, e.
The search tool is very easy to use and is self explanatory. The tool will also replace mirror coordinates if the check box is checked. Positive and negative values are compared to their absolute values, e. The tool can be used to enlarge or reduce the size of the antenna.
This is very useful when re-scaling an existing antenna design to a different frequency. The re-scaled antenna may require additional fine tuning. This must be done separately. To optimize an antenna quickly and accurately when the calculated results indicate that the model is not as required, use the following method.
This example is for a centre fed 12m dipole 10m above ground for a design frequency of This function is used to reduce the number of decimal places that are shown for the dimensions and calculated values. The program caters for 2 to 5 digits. Round works on all the parameters including wire coordinates, radius, and lumped-constant load.
MMANA-GAL has a special function that copies the original antenna, and will stack the antenna s either in a vertical or horizontal array. This is because once the stack has been created using the Make new description as new antenna button, there is no way to undo the result.
The pop up window shown below will appear. In the following explanation Basic-el refers to the original antenna that is being stacked. The Make Stack tool allows the Basic-el to be stacked in multiples of in the horizontal plane and of in the vertical pane.
The MMANA-GAL drop down menu offers 1,2,4 or 8 copies but an intermediate number can be entered by backspacing over the number and entering a new value. The stacking can ordered horizontally, vertically or by both planes simultaneously. The results can be checked by clicking on the View Tab. The antennas are spaced in term of wavelength WL either as a number 1. The spacing of the antennas in the horizontal and vertical planes can be changed if necessary. To make your stacked design permanent, push the Make new description as new antenna button in the Stack window.
However once this done it is impossible to revert back to the original design, i. The Make Stack tool is used to implement a phased driven or a unbalanced driven antenna. Note that when making a vertical stack, the vertical position choice affects the calculation with respect to ground.
An error message will be displayed if the antenna heigh t places the antenna "below ground "! It is also important to note that the vertical position is not considered in the free space calculation. However, it occasionally easier for the designer to use the polar coordinates i.
This pop-up menu provides a polar coordinates editor. The menu facilitates the definition of any wire that is composed of two or more sub-wires having different radii, also known as a "taper schedule". Typically HF Yagi antennas are made with two or more telescoping sections of different sized tubes to reduce droop of the antenna and reduce its wind resistance.
The tool simplifies the designs these types of antennas by using special parameters. For instance, an antenna element consist of 3 tubes of differing diameters Diameter Length 30 mm 2 m 25 mm 1. An antenna element setting of If L3 is set to 0, L2 automatically becomes In the antenna View window, the tapered element is displayed with the connecting points marked with a blue square. Right click on the element to verify the combination. You should pay careful attention to the segmentation for a combination of elements.
Even if you specify equal segmentation, the actual segmentation will not follow this rule because of the element's construction.
You have to adjust the DM2 value using the Antenna View and increase the value to 50 or Automatically optimizes the antenna giving consideration to various parameters. Select the Optimization in the view menu or push the Optimization button in the calculation window to open the optimization window. The goals of the optimization are:. In most cases, these parameters are in the 'trade-off' condition.
You can select the parameters that you focus on using the slide bars in the top of the window. As you slide the bar to right, the selected target is prioritized.
As you slide the bar to the left end, the target is ignored. This is useful to observe the antenna behavior from the viewpoint of the height or frequency. Push the Advanced button to set the target at length. Push the Band setting button to get the dialog box, with which you can specify the band frequency and the source. This is useful for optimizing a multi-band antenna.
Matching circuit is one of the hairpin match, capacitance match, and any Z. The hairpin match has minus jX capacitive and the capacitance match has plus jX inductive. Current optimization attempts to maximize or minimize the specified pulse point. You can set the parameters above as up to variables. Hit return key or click on the type field to display the type selection pop-up menu. Hit return key on the what field to pop the menu up. Input a value manually to other fields.
These are most basic variables. If the specified wire changes its coordinates, the connected wires also changes together to keep them connected. This method should be useful for the fine-tuning. Unit is always meter. You can change the wire length and angle with respect to the reference point in the polar coordinates.
This is useful for optimizing the length or the angle of the inverted V and V beam. It should be noted that you must not set the element position or space as the variable if you change the X-axis.
When the coordinate of the wire is changed, the connected wire moves together with it. The step unit is meter or degree. The parameters that define the element can be set as the variable in the optimization. For a yagi antenna, for example, they are the element space, position, and width. For a loop antenna, they are space, positio, perimeter, etc. If you want to change two loads in both ends of the element e. Unit of L is uH. Unit if C is pF. Unit of R is Ohm.
Unit is MHz. If your target antenna is a multi-bander, do not use the frequency as the variable. Unit of the phase is degree. Unit of the voltage is V. Unit is meter. If you set space in the what box, the vertical and horizontal spaces are changed at the same time. If you put 0 to the association box, the parameter changes freely as an independent variable.
If you put a plus number, it is assumed to have the same variable that the number points to. If you put a minus number, it is assumed to have the same variable negated that the number points to. You can put a simple equation, too.
It works like a primary spreadsheet. You define two variables, Y1 and Y2, which specify the trap positions. You can make use of the automatic association by right click at the variable box.
This method can be used to move the center wire of hentenna or tri-hat antenna. Pitch specifies the minimum step of variable change in either an absolute value or a percentage.
Large pitch makes the convergence fast but will not reach the best result. Min and Max defines the range of the variable. The variable does not become smaller than Min or larger than Max. You could specify other variable with followed by the variable number.
If you put 1 in the Max box for example, the Max value is set the value of variable 1. It is a good idea to see how the antenna dimension is being changed in the antenna view window during the optimization.
Push the Del ete button to delete the variable where the cursor resides. If the space check box is checked, the element space is used. If not, the absolute position of the element is used. Push the Element edit button to start an element selection view. Move the cursor to the variable that you want to vary in the optimization procedure, and push the OK button. If you want to do this with the 3-D view, select the wire selection tab.
Click the wire you want to add as a variable. Push the OK button. The wire already registered as a variable is shown in red. Step in absolute values : if checked, put an absolute value to the pitch. If not checked, put a percentage value. It shortens the calculation time, but degrades the accuracy particularly for the high-frequency antenna with a ground.
Display log : the intermediate states of the optimization procedure are displayed in the log window. Push the Start button to start the optimization. Even during the optimization, you can see the wire definition, the antenna view, or the far field pattern in real time. You can run the optimization in one window and design an antenna in the other window. The optimization routine would not always judge the result, which one thinks the best, is the best.
This might be due to the fact that the rate of evaluation is different from that the designer expects. You can read the optimization log by pushing the Optimization log button at the bottom of the Optimization window.
It shows up to latest steps of the optimization. You can select one of the steps and get it back to the optimization window so that you can manually pick out the optimization result you think best. Changing one parameter at a time to maximize the target value and repeating it for other parameters as well, gives fast convergence and good results. This procedure, however, would not always give the real optimized solution that the one-by-one method gives. It could terminate the optimization just after finding a local minimum.
If you are not satisfied with the result, change the parameter manually and retry the optimization. The result could depend on the parameter order. It is a good idea to put the most effective parameter in the first place of the variable parameter list.
Pursuing the gain often results in the low impedance. The very low impedance makes the sustainable bandwidth narrow, and the wire loss cannot be ignored. It is difficult to implement the very low impedance antenna in the real world. Consider SWR in the optimization for obtaining reasonable results.
Only the first feeding information is displayed. To keep the performance even in the band edge, put the band edge frequency as well. However, it increases the calculation time for the convergence. I am not sure if you could achieve good results. In case of Uda-Yagi antenna, the moment method is weak in the calculation speed, so I recommend you use another analyzing tool that uses the electromotive force method.
Set the target to the SWR minimization and start the optimization. Set the target to the matching circuit and star the optimization. Do not set the target to SWR or jX.
Put 0 to jX. You may put a little value to jX. Bear in mind that you have to keep the front-end and back-end elements fixed. In other words, you use the positions of the elements except for these two elements. To automatically register the element position as a variable, you should uncheck the Distance from the active element box in the Edit element window. MMANA-GAL analyzes the relative positions of the elements and assigns the variables in the order of the radiator, reflector, and directors d1-dn.
If two or more elements have the identical X-axis value, they are assumed to be connected. In such a case, right click on the optimization window to get the pop-up menu, select the element association.
You can make association the element with the other element that have different X value. This technique would be useful for the antennas, such as a surface antenna, which has many elements in the same size and space. You may change the value as you like. The pop-up menu provides a means to give the identical pitch to the all variables.
It should be useful for the antenna construction to have the resonance frequency of each element by using the antenna simulation. Put the source to the target element. Set the frequency as the variable and set jX to the goad.
First run the calculations for 7. This tool enables comparisons to be made of any previously stored calculations. You can compare changes made to the same antenna or compare the far field plots of different antennas. The Far field plot screen shows the beam pattern. The left chart shows the horizontal pattern. The right chart shows the vertical pattern. The vertical pattern is obtained by slicing the horizontal pattern with the vertical plane that includes the X-axis.
The horizontal pattern is obtained at the horizontal plane that has an elevation peak. To change the elevation, push the Elevation button. The angle of resolution in both horizontal and vertical patterns is 1 degree. The elevation, on the other hand, has 0.
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