using em quest viewer supplement

8/6/2019 Using Em Quest Viewer Supplement

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Using EMQuest Viewer

for Antenna Pattern FilesSupplemental Guide


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| iii

Table of Contents

Introduction ................................................................................................................................................4Step 1: Download EMQuest Viewer and Pattern Files .......................................................................4Step 2: Open a Pattern File ................................................................................................................8Step 3: Find the 3 dB or Half-power Beamwidth...............................................................................10Step 4: Find Front-to-back Ratio and Sidelobe Level .......................................................................15

ETS-Lindgren L.P. reserves the right to make changes to any product described herein in order to improve function, design, or for

any other reason. Nothing contained herein shall constitute ETS-Lindgren L.P. assuming any liability whatsoever arising out of the

application or use of any product or circuit described herein. ETS-Lindgren L.P. does not convey any license under its patent rights

or the rights of others.

Copyright 2008 by ETS-Lindgren L.P. All Rights Reserved. No part of this document may be copied by any means

without written permission from ETS-Lindgren L.P.

Trademarks used in this document: The ETS-Lindgrenlogo and EMQuestare trademarks of ETS-Lindgren L.P.

Revision Record | MANUAL,USING EMQUEST VIEWER | Part #399292, Rev. A

Revision Description Date

A Initial Release June, 2008

Internet Addresshttp://www.ets-lindgren.com

USA1301 Arrow Point DriveCedar Park, TX 78613 USATel: +1.512.531.6400Fax: +1.512.531.6500Email: [email protected]

FinlandMekaanikontie 1, 27510Eura, FinlandTel: +358.2.838.330Fax: +358.2.865.1233Email: [email protected]

Japan4-2-6, KohinataBunkyo-ku, Tokyo 112-0006 JapanTel: +81.3.3813.7100Fax: +81.3.3813.8068

Email: [email protected]

ChinaB506 Technology Fortune CenterNo. 8 Xue Qing RoadHaidian DistrictBeijing 100085

ChinaTel: +86.010.827.30877Fax: +86.010.827.55307Email: [email protected]


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4 | Using EMQuest Viewer for Antenna Pattern Files

Introduction

This document describes how to use EMQuest Viewer to identify the beamwidths and the front-to-back ratio from the

pattern information of ETS-Lindgren antennas. Steps to obtain the typical parameters that can be obtained from the

normalized radiation pattern are provided.

Customers interested in using the antenna as a feed to a reflector can use the same procedure to obtain a

3 dB, half-power, or 10 dB beamwidth.

Radiation pattern information is available for most ETS-Lindgren antennas. The antennas have been measured at the

ETS-Lindgren A2LA-certified Calibration Lab. Two anechoic chambers for antenna measurement are located at the

ETS-Lindgren facility in Cedar Park, Texas:

Tapered anechoic chamberFor measurements 400 MHz to 6 GHz

Rectangular anechoic chamberFor measurements 700 MHz to 18 GHz

Step 1: Download EMQuest Viewer and Pattern Files

1. Go to www.ets-lindgren.com.

2. On the Products menu, click Software.


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Using EMQuest Viewer for Antenna Pattern Files | 5

3. On the Software page, click EMQuest Viewer.

4. On the EMQuest Viewer page, click Download EMQuest Viewer.

The EMQuest Viewer page provides the minimum system requirements and recommended system

requirements to run EMQuest Viewer.


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5. Follow the steps to download and save the ZIP to the desired location on your computer.

Click the ZIP to extract the EMQuest Viewer executable.

Click the executable to install EMQuest Viewer.

6. On the EMQuest Viewer page, click View Antenna Patterns to Download.

Some of the antenna pattern files are full 3D patterns and some are principal plane cuts of the pattern. Later

steps in this guide include instructions to extract the parameters for 3D patterns and 2D principal planes.


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7. Move the pointer over an antenna model to display a picture of the antenna.

8. Click the antenna model name to download the pattern file.

9. Follow the steps to download and save the pattern file to the desired location on your computer.

Go to page 8 to open the pattern file with EMQuest Viewer. You will use EMQuest Viewer to display the pattern and

search for parameters.


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5. Large pattern files may display a warning indicating the file may take additional time. Click Yes.

This warning typically appears for 3D patterns with many frequency points.

The pattern file displays in the window.

Go to page 10 to f ind the 3 dB or half-power beamwidth.


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Step 3: Find the 3 dB or Half-power Beamwidth

The half-power beamwidth quantifies the width of the main beam of the antenna. It is the angular separation of the points

of the main beam of the power pattern where the power equals one-half of the maximum value. Several EMC standards

call for the beamwidth and require that the entire Equipment Under Test (EUT) fall within the beamwidth of the antenna. Ifthe EUT does not fall within the beamwidth, then the antenna must be repositioned so that the entire EUT is covered

during emissions testing.

The 3 dB beamwidth can be found by looking at the pattern in polar format rather than 3D format. Following are the steps

to view a pattern in polar format.

1. With the pattern displaying in the EMQuest Viewer, click the Polar Plot button to display the pattern in polar

format.

2. To remove all of the lines except for the ones corresponding to the principal planes, right-click on the pattern.

The Graph Settings window will display.


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3. Click the Traces tab, and then click Hide All.

The check boxes will clear, and all the traces will be hidden.

4. In the list of traces click to select the traces you want to display. For the principal planes, click the traces

corresponding to 0, 90, 180, and 270.

To change the line weight and color of a trace, click the trace and then select the desired characteristic in Line

Type and Trace Width.

Click OK.


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5. To change the scale for the 3 dB points on the main beam, right-click on the pattern for the Graph Settings

window.

6. Click the Scale tab and type 3 in the Y Step box.

For example, a 3 dB Y-axis setting displays the 3 dB or half-power beamwidth.

To use your ETS-Lindgren antenna to illuminate reflectors, you will want the find the 10 dB beamwidth.

Type 10 in the Y Step box.


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7. Click Ok to display the plot.

In this example, the traces cross the 3 dB line at about 30and 35for each plane. The beamwidth is 60on

one plane and about 70on the other.

8. To select a different frequency, right-click on the plot to display the Graph Settings window, click the

Dimension Depth tab, and then move the slider to the desired frequency.

Click OK.


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The 3 dB beamwidth is shown in both principal planes. In this example, on one plane the beamwidth is

about 60( 35) and on the other it is about 70(35).


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Step 4: Find Front-to-back Ratio and Sidelobe Level

1. Using the steps in the previous sections, open the antenna pattern file and obtain the polar plot in the two

principal planes.

2. Right-click on the plot to display the Graph Settings window.

3. Click the Scale tab and type the Y-axis setting in the Y Step box. For an example, see step 6 on page 12.

4. Click the Dimension Depth tab, and then move the slider to the desired frequency.

Click OK.

5. Click the Cursor Readout button, and then move your cursor over the graph.

6. Move the cursor to the largest sidelobe. The cursor readout will display the level and angle of the sidelobe. The

level of the largest sidelobe is the sidelobe level for that given plane and frequency.

In this example, the sidelobe level is -13.7 dB.


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7. Move the cursor to point to the pattern on the opposite direction of the main beam. The value read on the cursor

readout is the front-to-back ratio at that particular frequency.

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