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NeoScan Manual Part C: Near Field Mapping

3,515 bytes added, 21:30, 8 March 2017
/* 3D Plots Page */
Select “What Axis to Scan First?” By default the program start scanning Y-axis first. In either case the scan data is written in a file in the same format, see Figure 4.11.
<center>[[Image:neoscanfig_4_11.png|thumb|center|600px450px|<i><b>Figure 4.11</b>: Setting directions of scan using “What Axis to Scan First?”
.</i>]]</center>
</p>
It is assumed that the scan parameters are set and the scan measurement setup has been setup. In order to start the scan, press “Scan Control” tab in [[NeoScan]] Mapping Utility program (Figure 4.13).
 
<center>[[Image:neoscanfig_4_13.png|thumb|center|600px|<i><b>Figure 4.13</b>: Scan Control Tap in NeoScan Mapping Utility Program.</i>]]</center>
 
<ol>
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<p>
Press “Start Scan” button to start the scan.
</p>
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<p>
The program displays 2D Amplitude and 2D phase contour plots of the measured amplitude and phase during the scan, as shown in Figure 4.14. Graphs are rescaled continuously during the scan. This enables the users to monitor the status of the scan. For instance, any sudden change or any instrumental failure can appears as anomalous pattern in either 2D plots.
</p>
</li>
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<p>
The “Pause Scan” and “Stop Scan” buttons control the scan process. During scanning, use “Pause Scan” to pause temporarily the scanning. Pressing the “Stop Scan” button during scanning, will stop the scanning process.
</p>
</li>
<li>
<p>
The “Plot Display?” key allows a user to display 2D Amplitude graph in dBm or μV unit. Similarly, “Current Signal” and “Current phase” in information panel present the lock-in amplifier current readings during the scan (Figure 4.15).
</p>
<center>
[[Image:neoscanfig_4_14.png|thumb|center|600px|<i><b>Figure 4.14</b>: 2D Amplitude (in dBm unit) and 2D phase contour plots of the measured amplitude and phase during the scan.</i>]]
<br>
[[Image:neoscanfig_4_15.png|thumb|center|600px|<i><b>Figure 4.15</b>: 2D Amplitude (in μV unit) and 2D phase contour plots of the measured amplitude and phase during the scan.</i>]]
</center>
 
<ul>
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<p>
A user can check the “Elapsed Scan Time” and view the current X and Y position of the probe from the information panel (see Figure 4.16).
</p>
</li>
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<p>
During the scan, there is no access to other tabs or pages in [[NeoScan]] Mapping Utility program.
</p>
</li>
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<p>
When a signal falls below -150 dBm, a warning message appear in Information Panel indicates that “Detected a signal &lt; -150 dBm in Ch 1 -- much below the noise level.” You may check the data later.
</p>
</li>
</ul>
</li>
</ol>
  During The “Stop” button stops the application. To close (kill) the scan, there is no access to other tabs or pages in [[NeoScan]] Mapping Utility window click on exit button [[Image:icon_Exit.png]] on the top far right in the LabView user interface. To re-start running the programpress the start button [[Image:icon_Start.png]] located on the top left in the LabView window, see Figures 4.5 and 4.16.
When a signal falls below -150 dBm, a warning message appear in Information Panel indicates that “Detected a signal < -150 dBm in Ch 1 -- much below the noise levelcenter>[[Image:neoscanfig_4_16.” You may check the data laterpng|thumb|center|600px|<i><b>Figure 4.16</b>: A completed scan of a Patch Antenna by NeoScan system.</i>]]</center>
The “Stop” button stops the application. To close (kill) the [[NeoScan]] window click on exit button on the top far right in the LabView user interface. To re-start running the program press the start button located on the top left in the LabView window, see Figures 4.5 and 4.16.4.3 === The [[NeoScan]] Scan Data===
During each scan, both the magnitude and the phase of a particular electric field component at a plane are measured. When the scan is completed, data are written in .DAT files in your defined (created) project folder, say “patch_2.349GHz,” in the parent folder, i.e.
During a scan, data is collected and immediately displayed by [[NeoScan]] Mapping Utility program. However, data will be written into the files at the end of the scan.
<center>[[Image:neoscanfig_4_17.png|thumb|center|600px|<i><b>Figure 4.17</b>: Contents of data file E_X_Dir.DAT in patch_2.349GHz folder</i>]]</center>
 
== [[NeoScan]] Visualization Utility ==
During each scan, both the magnitude and the phase of a particular electric field component at a plane are measured. Measured data can easily be interpreted and understood when displayed as 2D or 3D graphs. Visualization of the [[NeoScan]] scan data are realized by LabVIEW based programs. It plots the amplitude and the phase of the measured field distribution on a horizontal plane after the scan. [[NeoScan]] Visualization Utility includes three pages: Settings, Near Field Maps, and Far Field Patterns.
[[Image:icon_Plot.png|right]] Open the [[NeoScan]] Visualization Utility program from Desktop or Windows Explorer by double clicking on the NeoScanVisual icon [[Image:icon_Plot_small.png]]. By default, [[NeoScan]] Visualization Utility program opens up with “Settings” page (Figure 5.1).
<center>[[Image:neoscanfig_5_1.png|thumb|center|600px|<i><b>Figure 5.1</b>: NeoScan Visualizarion Utility Program.</i>]]</center>
==== Settings Page ====
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
[[NeoScan]] Visualization Utility
During each scan, both the magnitude and the phase of a particular electric field component at a plane are measured. Measured data can easily be interpreted and understood when displayed as 2D or 3D graphs. Visualization of the [[NeoScan]] scan data are realized by LabVIEW based programs. It plots the amplitude and the phase of the measured field distribution on a horizontal plane after the scan. [[NeoScan]] Visualization Utility includes three pages: Settings, Near Field Maps, and Far Field Patterns.
 
Open the [[NeoScan]] Visualization Utility program from Desktop or Windows Explorer by double clicking on the NeoScanVisual icon. By default, [[NeoScan]] Visualization Utility program opens up with “Settings” page (Figure 5.1).
 
5.1.1 Settings Page
By default [[NeoScan]] Visualization Utility program consider the “Project Folder”:
 
C:\Users\[[NeoScan|neoscan]]\Documents\[[NeoScan]]\Projects
 
as the parent folder in which all saved data are stored.
In order to view the plots of scan data:
<ol>
<li>
<p>
Press “Open File 1” button as shown in Figure 5.1. This opens up the dialog window, where direct you to the project in parent folder where you want to open a data file, see Figure 5.2.
<center>[[Image:neoscanfig_5_2.png|thumb|center|600px|<i><b>Figure 5.2</b>: Selecting a data file (E_X_Dir.DAT) from project folder (patch2.349GHZ) from the dialog window.</i>]]</center>
</p>
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<p>
Choose the desired data file – e.g., E_X_Dir.DAT in project folder patch2.349GHz – and then press “OK” button in the dialog window.
</p>
<ul>
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“Information Panel” and “Project Description” will display all scan information regarding the selected project and scan (Figure 5.3).
Similarly, the user can open file 2, and <center>[[Image:neoscanfig_5_3.png|thumb|center|600px|<i><b>Figure 5.3 to display simultaneously</b>: Project Description Panel and Information Panel in NeoScan Visualization Utility program.</i>]]</center></p></li></ul>
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Similarly, the user can open file 2, and 3 to display simultaneously.
</p>
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Press “Near Field Maps” tab from [[NeoScan]] Visualization Utility program to view the plots.
</p>
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</ol>
 
==== Near Field Maps Page ====
5.1.2 Near Field Maps Page
[[NeoScan]] Near Field Maps page displays either 2D or 3D plots of the amplitude and phase distribution of the scanned field from saved files. It includes 2D Plot page and 3D Plot page.
 
  5.1.3 ==== 2D Plots Page====
When you enter “2D Plot” page, 2D contour plots for amplitude and phase distributions of the scanned field are plotted and the maximum and minimum of their values are displayed in the boxes next to the graphs (Figure 5.4).
<center>[[Image:neoscanfig_5_4.png|thumb|center|600px|<i><b>Figure 5.4</b>: 2D plots in NeoScan Near Field Maps Page.</i>]]</center>
 
<ul>
<li>
<p>
By default, the program plots fields in V/m units. You can use the key labeled “Amplitude Unit?” to display them in dBV/m (Figures 5.4 and 5.5).
<center>[[Image:neoscanfig_5_5.png|thumb|center|600px|<i><b>Figure 5.5</b>: 2D Amplitude graphs in units of dBV/m (left) and V/m (right).</i>]]</center>
</p>
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The “Phase Shift” knob adds an angular shift (in degree) to the phase distribution (Figure 5.6).
<center>[[Image:neoscanfig_5_6.png|thumb|center|600px|<i><b>Figure 5.6</b>: Effect of 90° phase shift on 2D Phase graph.</i>]]</center>
</p>
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The Phase Threshold knob will sets any phase below a minimum field threshold (in V/m) to zero. Figure 5.7 compares the 2D Phase graph without a phase threshold (left) with the one with a phase threshold when the minimum field is set to 10 V/m (right).
<center>[[Image:neoscanfig_5_7.png|thumb|center|600px|<i><b>Figure 5.7</b>: 2D Phase graphs without (left) and with a phase threshold, setting the minimum field to 10 V/m (right).</i>]]</center></p></li><li><p> By default, [[NeoScan]] Visualization Utility program fits the 2D graphs into the square window. If the DUT is other than a circle or regular polygon such as square, equilateral triangle, etc. you must choose the “Maintain Ratio” option in “View Fit?” in order to keep the object proportional. As an illustration, Figure 5.8 presents the comparison of 2D amplitude plots for field distribution of a 12 mm × 220 mm (rectangular) slotted waveguide antenna with different view options when “View Fit?” key is set to “Fit to Window” (left plot) and when “Maintain Ratio” option is chosen (right plot).
<center>[[Image:neoscanfig_5_8.png|thumb|center|600px|<i><b>Figure 5.8</b>: Comparison of 2D amplitude plots for field distribution of a slotted rectangular waveguide antenna with different view options; When “View Fit?” key is set to “Fit to Window” (left plot) and when “Maintain Ratio” option is chosen (right plot).</i>]]</center>
</p>
</li>
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Press “Save Graphs” button to save all plots. The plots associated with a project are saved in a folder called “Plots” within the same folder.
</p></li><li><p>
You can zoom in and out the graphs by clicking on the zoom button (Figure 5.4).
</p></li>      </ul>
 
    ==== 3D Plots Page====
To view 3D plots, press the “3D Plots” tab in Near Field Maps page (Figure 5.9).
<ul>
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<p>
3D Amplitude graphs can be plotted either in dBV/m or V/m using the key labeled “Amplitude Unit?”
</p>
</li>
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The “Phase Shift” knob adds an angular shift (in degree) to the phase distribution.
</p></li><li><p>
Users can choose the plot style using “Plot Style” dropdown window (Figure 5.10). It includes:
</p>
 
<ul>
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cwLine
</li>
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cwPoint
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cwLinePoint
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cwHiddenLine
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cwSurface
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cwSurfaceLine
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cwSurfaceNormal
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cwContourLine
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cwSurfaceContour
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</ul>
The default format is “cwSurface.”
</li><li><p>
To adjust the graph degree of transparency use “Transparency” knob or Transparency Entry Box as shown in Figure 5.11.
</p>
</li>
</ul>
<center>
[[Image:neoscanfig_5_9.png|thumb|center|600px|<i><b>Figure 5.9</b>: 3D plots in NeoScan Plot Utility Page (with cwSurface plot style).</i>]]
<br>
[[Image:neoscanfig_5_10.png|thumb|center|600px|<i><b>Figure 5.10</b>: 3D plots in Fig. 5.9 with cwPoint plot style.</i>]]
<br>
[[Image:neoscanfig_5_11.png|thumb|center|600px|<i><b>Figure 5.11</b>: Effect of transparency level on 3D plots: 0% transparency level (left) and 50% transparency level (right).</i>]]
</center>
The “Stop” button stops the application. To close (kill) the [[NeoScan]] window click on exit button [[Image:icon_Exit.png]] on the top far right in the LabView user interface. To re-start running the program press the start button [[Image:icon_Start.png]] located on the top left in the LabView window, see Figure 5.1.
5.1.5 ==== Far Field Patterns Page The far field pattern measurement and utility are discussed in details in section 6.====
The far field pattern measurement and utility are discussed in details in section 6.
 
 
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