Antenna Plots

I can be contacted at E-mail address:- web@g3tvu.co.uk

If the generic antenna radiation pattern forms included with Radio Mobile do not meet your needs, there are a number of spreadsheets available which enable you to enter your own radiation patterns for specific antennas.

Radio Mobile reads an antenna pattern definition text file with an extension of ***.ant which is contained in the 'Antenna' folder of RM. The file format is a list of gain values for an antenna at 1˚ intervals, but shown from a maximum gain of 0dB. Thus the list shows the antenna gain as -ve dB's relative to the maximum antenna gain which produces an Antenna Pattern for RM and the actual antenna gain value is entered in the 'Radio Operating System' allocated to the Unit on the 'Network Properties' (Ctrl+N) pane.

There are three versions of antenna pattern files recognised by RM:

*Version 1*	Contains a list of 360 entries for the Azimuth pattern starting at 0˚ (Maximum antenna gain) set as 0dB, with the gain relative to this direction (in -ve dB's) entered at 1˚ increments.
Version 2	A listing of 541 entries - first the 360 Azimuth relative gain values as Version1 above, followed by relative Elevation values from +90˚ to -90˚. This version produced an Azimuth+Elevation plot with simulated values for reverse elevation angles.
*Version 3*	A listing of all 720 entries for the full Azimuth and Elevation antenna characteristics. The first entry at 0˚ Azimuth set at 0dB as Version 1, followed by the remaining 359 entries at 1˚ for the Azimuth pattern. The next 180 entries are for Elevation angles of +90˚ to -90˚ followed by the additional Elevation entries for -91˚ to -180˚ and then +179˚ to +91˚ to complete the 360˚ Elevation pattern.

The first two spreadsheets, 'AntDiag.xls' and 'Antenna Pattern Creator with FCC relative.xls', allow Version1 2D Azimuth antenna data to be entered at 10˚ intervals but require the data to be converted to -dB's before entry. The program then performs linear interpolation between the 10˚ points and generates the 1˚ list for copying and import into RM. These spreadsheets are available via the links, my Downloads page, or from the Group Files section.

Following the addition of full 360˚ 3D antenna patterns with V9.6.4 of RM, I produced a new spreadsheet called '3D-360 degree gain plot' shown below (but which has now been updated).

The new updated version of the above spreadsheet is one named '3D-360 degree antenna plot accepting phased verticals'. This sheet accepts actual antenna gain data and also generates patterns where the maximum Elevation gain lies below 0° - in this case the actual 0° gain has to be entered as the Azimuth gain for all angles to generate the *.ant file.

With the new spreadsheet actual Azimuth and Elevation gain data may be entered in 5° or 10° increments as desired. Where 10° entries are used, the 5° data points should be left at 0dB, and then the 10° points will be interpolated into the 1° steps required by RM ***.ant files. Where 5° data is entered this will be interpolated to 1° steps.

The datasheet Azimuth antenna gain entries should be entered into the Green data area - with the corresponding Green chart showing the pattern entered.

But make sure that you enter your actual antenna Azimuth gain at 0°!

Elevation antenna gain entries should be entered into the Blue data area - with the corresponding Blue chart showing the pattern entered. Make sure that you examine the sheet Elevation degree format if you are pasting 5° data from Eznec, otherwise you will obtain an incorrect pattern shape but this will be shown immediately on the spreadsheet charts.

Note that any data entered into the white boxes in the green or blue entry areas will be ignored - this is to allow pasting of gain values for Omni antennas into the whole column.

Macro's need to be enabled to perform the selective Copy function!

1) The original:

3D - 360 degree gain plot

With this spreadsheet maximum antenna gain for Azimuth and Elevation had to occur at 0° or the resulting pattern shown on the RM Antenna pattern viewer would overflow - this has been solved in -

2) The new version:

3D-360 degree plot accepting phased verticals

The sheet has now been revisited to provide a better chart display where the data entered had a very large dynamic range, as for instance when using data derived from Eznec calculations.

(Click here for Eznec data entry information)

The sheets contains a macro to perform the required 'Data copy' function:

'Ctrl+F' copies the Full Azimuth plus Elevation (Yellow plus Tan) (Version 3) data to the clipboard.

Next the data needs to be pasted into Notepad (or other text editor), and then using 'Save as' select 'File type' to be 'All Files', and enter 'Your_name.ant' as the file name. The file can then be saved in the RM Antenna folder for use.

This spreadsheet is protected to avoid entries into critical areas, but your data can be manually copied from the Yellow and Tan areas of the 'C' column if required - all 720 entries - hence the macro!

Instructions for use are included at the top on the spreadsheet, but are repeated here for information:

1) Actual Azimuth and Elevation gain data can be entered at 10° intervals by ignoring the 5° columns and leaving them at '0' - the 10° values will be interpolated.

2) Enter datasheet Azimuth gain data in the Green area with the plot being displayed on the Green chart.

But make sure that you enter your actual antenna Azimuth gain at 0°

3) Enter datasheet Elevation gain data in the Blue area with the plot being displayed on the Blue chart.

4) To save the Azimuth data only use 'Ctrl+a' to copy the yellow interpolated data area to the clipboard

- paste into Notepad, and save as 'your_name.ant' using 'All Files' option.

5) To save Full Azimuth and Elevation data use 'Ctrl+f' to copy the 'yellow + tan' data area to the clipboard

- paste into Notepad, and save as ''you_name2.ant', using 'All Files' option.

6) To generate an Omni Azimuth pattern, enter the same gain into all Green area cells - but if the Elevation plot has its maximum gain below 0°, make sure you enter the Elevation pattern 0° gain value as the Azimuth gain!

- any values pasted into the white areas will be ignored.

Eznec data import:

If you wish to import data from Eznec into the spreadsheet, perform a 'Far Field' plot for Azimuth and Elevation at 5° intervals. This data can then be imported into a spreadsheet to enable the columns of data to be separated and copied for pasting into my 3D spreadsheet. If you use 'Paste Special/Values' for the data, the spreadsheet colour formatting will be maintained with the 5° data being ignored in the 10° column - and 10° data ignored in the 5° column.

Note that Eznec data output comes as a 0° to 360° listing for Azimuth, but only 0° to 359° are required by RM.

The Elevation data is in the same 0° to 360° format, but needs to be copied into the correct cells on the spreadsheet as RM uses +90° to 0° to -180° then +179° to +91° as the entry format shown in Version 3 above. The charts will show the interpreted pattern data on the spreadsheet.

Please note that if you wish to share your *.ant files with someone else that they should be zipped before attaching to an email, as additional characters can be added to these 'text format' files if sent as attachments.

Please keep checking back for updates/additions