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{{projectinfo|TutorialApplication| Designing A Slot-Coupled Patch Antenna Array With A Corporate Feed Network Using EM.Picasso|PMOM372ART PATCH Fig title.png|In this project, we will build and analyze a 16-element slot-based coupled patch antenna array with a microstrip corporate feed network.|*[[Building Geometrical Constructions in CubeCAD| CubeCAD]]*[[EM.Picasso]]

*SlotTracesSlot Traces

*Lumped ElementStrip Gap Circuit

The input signal power must be divided equally among 16 patch radiating elements. In other words, a 1:16 power distribution network is needed for this project. The design of a Wilkinson power divider is described in detail in [[EM.Picasso Tutorial Lesson 9: Designing a Microstrip Wilkinson Power Divider]]. An Ω-shaped microstrip ring is used to create a three-port network. The input and output microstrip lines all have a width of 2.4mm with Z₀ = 50Ω. The microstrip partial ring has a width of √2Z₀ = 70.7Ω and serves as the two quarter-wave arms of the Wilkinson power divider. It is determined that if a lumped 100Ω resistor is connected between the two output arms of this divider, better return loss and isolation levels are achieved. The figure below shows the geometry of the optimized 1:2 Wilkinson power divider.

==Building <table><tr><td>[[Image:Picasso L9 Fig14.png|thumb|left|480px|The geometry of the Array Structure==Wilkinson power divider with the lumped resistor.]]</td></tr></table>

The corporate feed network on the microstrip trace plane (PEC_1) consists entirely of rectangle and circle strip objects. For the Wilkinson power dividers, circle strips with unequal outer and inner radii and incomplete start and end angles are used just as you saw in Tutorial Lesson 7. A 50&Omega; microstrip line on the lower thin substrate has == Constructing a width of 2.4mm. Small circle strips of (outer) radius 2.4mm are used to provide a round bend junctions between two perpendicular microstrip line segments. Rather than a quarterFour-circle, a 3/4Element Patch Sub-circle shape is used to have some good overlap area over the conjoining line objects. This helps with a smoother and more consistent mesh in such junction areas. Array ==

Draw A binary H-tree structure is used to construct a 1:4 Wilkinson power divider network as shown in the following 9 circle strip objectsfigures below. In this case, all on PEC_2 trace plane, with the given coordinates and dimensions: network involves three ring-type Wilkinson power dividers. <table><tr><td>[[Image:ART PATCH Fig1.png|thumb|left|640px|The geometry of the four-element slot-coupled patch sub-array with a corporate feed network.]]</td></tr></table>

{| border="0"<table>|-<tr>| valign="top"|<td>| valign="bottom"|{| class="wikitable" style="text-align[[Image: center;"|-! scope="col"| Label! scope="col"| Host Trace! scope="col"| Object Type! scope="col"| Function! scope="col"| LCS Origin! scope="col"| LCS Rotation Angles! scope="col"| Outer Radius! scope="col"| Inner Radius! scope="col"| Start Angle! scope="col"| End Angle|-! scope="row"| Circle_Strip_1| PEC_2| Circle Strip| Wilkinson Power Divider 1| (-17mm, 0, 0)| (0&deg;, 0&deg;, 0&deg;)| 9ART PATCH Fig2.65mmpng| 8.25mmthumb| 20&deg;left| 340&deg;640px|The geometry of the four-! scope="row"| Circle_Strip_2| PEC_2| Circle Strip| Wilkinson Power Divider 2| (10mm, 62.5mm, 0)| (0&deg;, 0&deg;, 0&deg;)| 9.65mm| 8.25mm| 20&deg;| 340&deg;|element slot-! scope="row"| Circle_Strip_3| PEC_2| Circle Strip| Wilkinson Power Divider 3| (10mm, coupled patch sub-62array with the patches in the freeze state.5mm, 0)]]| (0&deg;, 0&deg;, 0&deg;)</td>| 9.65mm</tr>| 8.25mm| 20&deg;| 340&deg;|-! scope="row"| Circle_Strip_4| PEC_2| Circle Strip| Round Bend Junction| (-6.75mm, 61.3mm, 0)| (0&deg;, 0&deg;, 0&deg;)| 2.4mm| 0mm| 0&deg;| 270&deg;|-! scope="row"| Circle_Strip_5| PEC_2| Circle Strip| Round Bend Junction| (-6.75mm, -61.3mm, 0)| (0&deg;, 0&deg;, 0&deg;)| 2.4mm| 0mm| 90&deg;| 360&deg;|-! scope="row"| Circle_Strip_6| PEC_2| Circle Strip| Round Bend Junction| (20.25mm, 92.55mm, 0)| (0&deg;, 0&deg;, 0&deg;)| 2.4mm| 0mm| 0&deg;| 270&deg;|-! scope="row"| Circle_Strip_7| PEC_2| Circle Strip| Round Bend Junction| (20.25mm, -92.55mm, 0)| (0&deg;, 0&deg;, 0&deg;)| 2.4mm| 0mm| 90&deg;| 360&deg;|-! scope="row"| Circle_Strip_8| PEC_2| Circle Strip| Round Bend Junction| (20.25mm, 32.45mm, 0)| (0&deg;, 0&deg;, 0&deg;)| 2.4mm| 0mm| 90&deg;| 360&deg;|-! scope="row"| Circle_Strip_9| PEC_2| Circle Strip| Round Bend Junction| (20.25mm, -32.45mm, 0)| (0&deg;, 0&deg;, 0&deg;)| 2.4mm| 0mm| 0&deg;| 270&deg;|-|}</table>

Rectangle strip objects are used for microstrip line segments. Draw the following 16 rectangle strip objects, all on PEC_2 trace plane, with the given coordinates and dimensions:  {| borderclass="0wikitable"

| valign! scope="topcol"|Design Variable Name| valign! scope="bottomcol"|{| class="wikitable" style="text-align: center;"Optimal value

! scope="col"| Labelpatch_len! scope="col"| Host Trace! scope="col"| Object Type! scope="col"| Function! scope="col"| LCS Origin! scope="col"| LCS Rotation Angles! scope="col"| X Dimension! scope="col"| Y Dimension39.5mm

! scope="row"| Rect_Strip_1slot_len| PEC_2| Rectangle Strip| 50&Omega; Input Microstrip Feed Line| (-38mm, 0, 0)| (0&deg;, 0&deg;, 0&deg;)| 8mm| 2.4mm12mm

! scope="row"| Rect_Strip_2slot_wid| PEC_2| Rectangle Strip| 50&Omega; Input Line for Wilkinson Power Divider 1| (-30mm, 0, 0)| (0&deg;, 0&deg;, 0&deg;)| 8mm| 2.4mm5mm

! scope="row"| Rect_Strip_3stub_len| PEC_2| Rectangle Strip| 50&Omega; Output Line for Wilkinson Power Divider 1| (-7.95mm, 32.06mm, 0)| (0&deg;, 0&deg;, 0&deg;)| 2.4mm| 58.48mm|-! scope="row"| Rect_Strip_4| PEC_2| Rectangle Strip| 50&Omega; Output Line for Wilkinson Power Divider 1| (-7.95mm, -32.06mm, 0)| (0&deg;, 0&deg;, 0&deg;)| 2.4mm| 58.48mm|-! scope="row"| Rect_Strip_5| PEC_2| Rectangle Strip| 50&Omega; Input Line for Wilkinson Power Divider 2| (-2.75mm, 6218.5mm, 0)| (0&deg;, 0&deg;, 0&deg;)| 8mm| 2.4mm|-! scope="row"| Rect_Strip_6| PEC_2| Rectangle Strip| 50&Omega; Input Line for Wilkinson Power Divider 3| (-2.75mm, -62.5mm, 0)| (0&deg;, 0&deg;, 0&deg;)| 8mm| 2.4mm|-! scope="row"| Rect_Strip_7| PEC_2| Rectangle Strip| 50&Omega; Output Line for Wilkinson Power Divider 2| (19.05mm, 78.935mm, 0)| (0&deg;, 0&deg;, 0&deg;)| 2.4mm| 27.23mm|-! scope="row"| Rect_Strip_8| PEC_2| Rectangle Strip| 50&Omega; Output Line for Wilkinson Power Divider 3| (19.05mm, -78.935mm, 0)| (0&deg;, 0&deg;, 0&deg;)| 2.4mm| 27.23mm|-! scope="row"| Rect_Strip_9| PEC_2| Rectangle Strip| 50&Omega; Output Line for Wilkinson Power Divider 2| (19.05mm, 46.065mm, 0)| (0&deg;, 0&deg;, 0&deg;)| 2.4mm| 27.23mm|-! scope="row"| Rect_Strip_10| PEC_2| Rectangle Strip| 50&Omega; Output Line for Wilkinson Power Divider 3| (19.05mm, -46.065mm, 0)| (0&deg;, 0&deg;, 0&deg;)| 2.4mm| 27.23mm|-! scope="row"| Rect_Strip_11| PEC_2| Rectangle Strip| 50&Omega; Slot Feed Line| (30.125mm, 93.75mm, 0)| (0&deg;, 0&deg;, 0&deg;)| 19.75mm| 2.4mm|-! scope="row"| Rect_Strip_12| PEC_2| Rectangle Strip| 50&Omega; Slot Feed Line| (30.125mm, -93.75mm, 0)| (0&deg;, 0&deg;, 0&deg;)| 19.75mm| 2.4mm|-! scope="row"| Rect_Strip_13| PEC_2| Rectangle Strip| 50&Omega; Slot Feed Line| (30.125mm, 31.25mm, 0)| (0&deg;, 0&deg;, 0&deg;)| 19.75mm| 2.4mm|-! scope="row"| Rect_Strip_14| PEC_2| Rectangle Strip| 50&Omega; Slot Feed Line| (30.125mm, -31.25mm, 0)| (0&deg;, 0&deg;, 0&deg;)| 19.75mm| 2.4mm|-! scope="row"| Rect_Strip_15| PEC_2| Rectangle Strip| Resistor Line for Wilkinson Power Divider 1| (-7.95mm, 0, 0)| (0&deg;, 0&deg;, 90&deg;)| 5.64mm| 1mm|-! scope="row"| Rect_Strip_16| PEC_2| Rectangle Strip| Resistor Line for Wilkinson Power Divider 2| (19.05mm, 62.5mm, 0)| (0&deg;, 0&deg;, 90&deg;)| 5.64mm| 1mm|-! scope="row"| Rect_Strip_17| PEC_2| Rectangle Strip| Resistor Line for Wilkinson Power Divider 3| (19.05mm, -62.5mm, 0)| (0&deg;, 0&deg;, 90&deg;)| 5.64mm| 1mm|-|}  You will use array objects to represent the repetitive pattern of slot-coupled patch radiators. Specifically, you will build three array objects for the patch element on the top PEC_1 trace plane, the coupling slot on the middle ground plane PMC_1, and the microstrip open stub underneath the slot on the bottom trace plane PEC_2. The table below shows the coordinate and dimensions of the primitive or "parent" objects for each of these arrays. First, you have to draw these objects on the respective planes:  {| border="0"|-| valign="top"|| valign="bottom"|{| class="wikitable" style="text-align: center;"|-! scope="col"| Label! scope="col"| Host Trace! scope="col"| Object Type! scope="col"| Function! scope="col"| LCS Origin! scope="col"| LCS Rotation Angles! scope="col"| X Dimension! scope="col"| Y Dimension|-! scope="row"| Rect_Strip_18| PEC_2| Rectangle Strip| Microstrip Open Stub| (51.5mm, -93.75mm, 0)| (0&deg;, 0&deg;, 0&deg;)| 23mm| 2.4mm|-! scope="row"| Rect_Strip_19| PMC_1| Rectangle Strip| Coupling Slot| (45mm, -93.75mm, 0.787mm)| (0&deg;, 0&deg;, 0&deg;)| 1.5mm| 12mm|-! scope="row"| Rect_Strip_20| PEC_1| Rectangle Strip| Radiating Patch| (45mm, -93.75mm, 2.787mm)| (0&deg;, 0&deg;, 0&deg;)| 31.6mm| 31.6mm|-|}  Now, select each of the above primitive objects and use [[EM.Cube]]'s Array Tool to create a 1&times;4 Y-directed linear array of that object on the proper plane. Make sure that right trace group on the Navigation Tree is activated before creation of each array object. Use the table below for element count and spacing along the three principal directions.   {{Note|Once you create an array object, the array's local coordinate system (LCS) takes over the parent object's LCS. The array's LCS rotation angles are independent of the parent object's rotation angles.}}  {| border="0"|-| valign="top"|| valign="bottom"|{| class="wikitable" style="text-align: center;"|-! scope="col"| Label! scope="col"| Host Trace! scope="col"| Primitive Object! scope="col"| Array LCS Origin! scope="col"| Array LCS Rotation Angles! scope="col"| X Count! scope="col"| Y Count! scope="col"| Z Count! scope="col"| X Spacing! scope="col"| Y Spacing! scope="col"| Z Spacing|-! scope="row"| Rect_Strip_18| PEC_2| Rect_Strip_18| (51.5mm, -93.75mm, 0)| (0&deg;, 0&deg;, 0&deg;)| 1| 4| 1| 0| 62.5mm| 0|-! scope="row"| Rect_Strip_19| PMC_1| Rect_Strip_19| (45mm, -93.75mm, 0)| (0&deg;, 0&deg;, 0&deg;)| 1| 4| 1| 0| 62.5mm| 0|-! scope="row"| Rect_Strip_20| PEC_1| Rect_Strip_20| (45mm, -93.75mm, 0)| (0&deg;, 0&deg;, 0&deg;)| 1| 4| 1| 0| 62.5mm| 0

[[Image:PMOM370ART PATCH Fig3.png|thumb|left|640px|The geometry hybrid planar mesh of the 4four-element slot-coupled patch antenna sub-array with a corporate feed network.]]

 Next, define three lumped elements of "Resistor" type with a 100&Omega; value and place them in the middle of the line segments Rect_Strip_15, Rect_Strip_16 and Rect_Strip_17. Also define a default +XThe 4-directed deelement slot-embedded source on the line object Rect_Strip_1 and assign a default Port Definition observable to it. Define three Current Distribution observables for the PEC_1, PEC_2 and PMC_1 traces. Define a Far Fields Radiation Pattern observable with a 3&deg; Angle Increment for both Theta and Phi, and check its Frontcoupled patch sub-to-Back Ratio (FBR) checkbox. Your antenna array is complete at this point.   simulated using [[Image:PMOM371.png|thumb|380px|The Planar MoM Mesh Settings dialogEM.Picasso]]==Examining the Mesh 's planar method of the Planar Array== Similar moments (MoM) solver. An adaptive frequency sweep is performed to Tutorial Lessons 7 and 8, set the mesh density to 40 cells per effective wavelength. Open the Mesh Settings dialog and increase compute the minimum angle frequency response of defective triangular cells to 20&deg;. Also, check the checkbox labeled " Refine Mesh at Gap Locations". This is due to structure over the presence of three lumped elements on very narrow line objects. In frequency range [[EM2.Cube2GHz - 2.6GHz]]'s [[Planar Module]], lumped elements behave very similar to gap sources.  Generate and view the planar MoM mesh of your array structure on all three PEC_1, PMC_1 and PEC_2 planes. The mesh of the corporate feed network is the most complicated one and requires special attention. In particular, closely inspect the mesh at figures below show the junctions variation of microstrip line segments with the Wilkinson circular rings and the around the round corner bend junctions. Also examine the connections to the open stub sub-array. Connections to array objects might sometime be tricky in complicated configurations.   {{Note|If your planar structure involves a large number of interconnected objects, individual objects with curved shapes, many overlap regions and several gap sources or lumped elements, [[EM.Cube]]'s mesh generator may fail return loss with low mesh density valuesfrequency and its 3D far-field radiation pattern computed at 2. You may be asked to increase the mesh density4GHz.}}  

[[Image:PMOM372ART PATCH Fig4.png|thumb|800pxleft|480px|The Planar MoM mesh return loss of the 4-element slot-coupled patch antenna sub-array with a corporate feed networkover the frequency range [2.2GHz - 2.6GHz].]]

[[Image:PMOM373ART PATCH Fig5.png|thumb|350pxleft|Details 640px|3D radiation pattern of the planar mesh around the Wilkinson power divider4-element patch sub-array computed at 2.]]</td><td>[[Image:PMOM374.png|thumb|500px|Details of the planar mesh around the round corner bend junctions4GHz.]]

==Running Constructing a Planar MoM Analysis of the Antenna 16-Element Patch Array== Run a quick planar MoM analysis of your slot-couple patch array structure. The size of the linear system in this case is N = 3,546. At the end of the simulation, the following port characteristic values are reported in the Output Message Window:  S11: -0.197431 - 0.916521j S11(dB): -0.560162 Z11: 2.660904 - 40.306972j Y11: 0.001631 + 0.024702j Note that input match of the array has been seriously degraded compared to that of the single slot-coupled patch antenna you built in Tutorial Lesson 8. Visualize all three current distributions on the PEC_1, PEC_2 and PMC_1 trace planes. You may have to change the limits of the current plot for the feed network due to the presence of a few very hot spots around the line discontinuities.

[[Image:PMOM375ART PATCH Fig10.png|thumb|750pxleft|640px|The surface electric current distribution on geometry of the microstrip 16-element slot-coupled patch array with a corporate feed network of the array after limiting the plot values to 99% confidence interval.]]

[[Image:PMOM376ART PATCH Fig11.png|thumb|450pxleft|640px|The surface electric current distribution on the top patches geometry of the 16-element slot-coupled patch arraywith the patches in the freeze state.]]

[[Image:PMOM377ART PATCH Fig12.png|thumb|450pxleft|640px|The surface magnetic current distribution on the coupling slots hybrid planar mesh of the 16-element slot-coupled patch arraywith a corporate feed network.]]

Also visualize the 3D radiation pattern of your patch antenna array and plot the 2D Cartesian and polar graphs in The matrix size for this planar MoM simulation is N = 10,771. [[EM.Grid. Note the portion of the radiation pattern in the lower half-space (90° ≤ θ ≤ 180°). This is due Picasso]]'s LU solver was used to solver the radiation from the feed networklinear system. Open The total computation time including the Data Manager and view the contents of the data file "FBR.DAT". You will see a value of 2.304221e-002 for the front-to-LU decomposition, back ratio of the slot-coupled patch array. But it important to note that the computed FBR value is ratio substitution and computation of the total full 3D far -field value radiation pattern at θ = 180° to an angular resolution of 1&deg; along both the total far field value at θ = 0°azimuth and elevation directions was 150 seconds. A close inspection At the end of the patterns in the lower half-space reveals that the back lobes peak at θ = 130°planar MoM simulation, not at θ = 180°. The directivity of the antenna array is found to be 11following port characteristics are reported: S11: 0.15 447781 + 0.118984j S11(or 10dB): -6.47dB)682387 Z11: 123.053609 + 37.286922j Y11: 0.007443 - 0. 002255j

[[Image:PMOM378ART PATCH Fig13.png|thumb|left|640px|The 3D far-field radiation pattern of the slot16-coupled element patch antenna array with a corporate feed networkcomputed at 2.4GHz.]]

[[Image:PMOM379ART PATCH Fig14.png|thumb|400pxleft|480px|The 2D Cartesian graph of the YZ-plane radiation pattern of the slot16-coupled element patch antenna array.]]</td><td>[[Image:PMOM380.png|thumb|400px|The 2D Cartesian graph of in the ZX-YZ principal plane radiation pattern of the slot-coupled patch antenna array.]]

[[Image:PMOM381ART PATCH Fig15.png|thumb|400pxleft|480px|The 2D polar graph of the YZ-plane Cartesian radiation pattern of the slot16-coupled element patch antenna array.]]</td><td>[[Image:PMOM382.png|thumb|400px|The 2D polar graph of in the ZX-principal plane radiation pattern of the slot-coupled patch antenna array.]]

 [[Image:PMOM383.png|thumb|450px|The 3D radiation pattern of a single stand-alone slot-coupled patch antenna multiplied by a 4&times;1 array factor.]] ==Comparison with Array Factor Method== In Tutorial Lesson 8, you could have defined a linear array factor in the Radiation Pattern dialog of the slot-couple patch antenna. Had you done that, the computed radiation pattern would have corresponded to an array of slot-coupled patch antennas rather than the single stand-alone radiator appearing your project workspace. However, the array pattern computed in this manner does not account for the inter-element coupling effects. The figures below have been obtained by multiplying show the radiation pattern of surface electric current distribution maps on the single slot-coupled patch antenna by a 1&times;4 Y-directed array factor with an element spacing of 62.5mm. The directivity of the array is calculated to be 12.15 (or 10.89dB)and feed planes, which is fairly close to as well as the directivity of surface magnetic current distribution map on the array with the corporate feed network. Comparing the two sets of radiation pattern plotsmiddle ground plane, you can see that even the side lobe and nulls are very similar in both casesall computed at 2. The main difference, however, is in the back lobe characteristics4GHz.  

[[Image:PMOM384ART PATCH Fig16.png|thumb|400pxleft|640px|The 2D Cartesian graph of surface electric current distribution map on the YZ-feed network plane radiation pattern of a single stand-alone slot-coupled patch antenna multiplied by a 4&times;1 array factorat 2.4GHz.]]

[[Image:PMOM385ART PATCH Fig17.png|thumb|400pxleft|640px|The 2D Cartesian graph of surface electric current distribution map on the ZX-plane radiation pattern of a single stand-alone slot-coupled patch antenna multiplied by a 4&times;1 array factorradiators at 2.4GHz.]]

[[Image:PMOM386ART PATCH Fig18.png|thumb|400pxleft|640px|The 2D polar graph of surface magnetic current distribution map on the YZ-plane radiation pattern of a single stand-alone slot-coupled patch antenna multiplied by a 4&times;1 array factorcoupling slots at 2.]]</td><td>[[Image:PMOM387.png|thumb|400px|The 2D polar graph of the ZX-plane radiation pattern of a single stand-alone slot-coupled patch antenna multiplied by a 4&times;1 array factor4GHz.]]

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