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Rectangular Microstrip Patch Antenna with Designer Layers Stackup • Open Ansoft Designer

• Project > Insert Planar EM Design > None

• Layout > Layers … Stackup Tab

o Add Layer > Name: ground, Type: metalizedsignal

o Add Layer > Name: rogers, Type: dielectric

Change thickness to “31mils”

The material should be: “Rogers RT/duroid 5880 (tm)” with εr = 2.2

o Add Layer

> Name:

signal,

Type:

signal

Model Setup • Calculate the lengths and widths necessary for the patch antenna using the theory from

class – these are approximate numbers and will be modified later

• Use Ansoft designer to calculate the length and width of the 100ohm feedline to the patch:

o Project > Insert Circuit Design > None

o Schematic > Layout Stackup...repeat the stackup layers to create the same stackup as

before

o Circuit > Add Model Data > Add Substrate Definition…

In the dielectric area: H = 31mils, Er = 2.2

o Circuit > TRL > Microstrip > Single, Select Substrate > OK

o Set Z0 = 100, E = 180, Frequency = 10, H = 31mil (Make sure Dimension is in mm and

GHz) ……… PUSH SYNTHESIS then OK

o Note the values of W and P for the microstrip that you have created this is the width

and the

length

of

the

100

ohm

transmission

line

that

you

will

create

in

the

planar

tool!

• BACK TO YOUR PLANAR DESIGN

• Draw > Primitive > Rectangle, draw a random rectangle – this will be your patch antenna

o Double click the new rectangle and define its points:

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Point A should be 0,0 Point B should be L,W where L and W are the Length and

Width that you calculated for the PATCH

• Draw > Primitive > Rectangle, draw a random rectangle – this will be your feedline antenna

o Double click the new rectangle and define its points:

Point A should be 0,0 Point B should be W,‐P where W and ‐P are the Width and

Length that Ansoft calculated for the feedline – note that you should make the

length value NEGATIVE so that the edges of your two rectangles are touching

• Select both rectangles, Draw > Align > Center Horizontally > OK

• Your Patch antenna with feedline is finished:

Excitation Setup

Edit > Select Edges, select the bottom edge of your transmission line:

W

L

100Ω Transmission line

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• In the Project Window, Excitation > Add Port

• In the Project Window, Excitation > Add Port

• Edit > Select to get back to a regular cursor

• Double click

the

PORT

itself,

go

to

the

Planar

EM

Tab

and

set

the

“Renormalize”

to

100+0i

Analysis Setup • Planar EM > Solution Setup > Add Solution Setup

o Since this is a geometrically simple structure, a fixed mesh will give an accurate

result. Use a fixed mesh with a frequency of 10.0 GHz.

• Planar EM > Solution Setup > Add Frequency Sweep

o Add a frequency sweep from 9.0 GHz to 11.0 GHz with 11 points

o Change the type so that the Generate Surface Current box is checked.

• Planar

EM

>

Analyze

Plotting Results • In the Project Window, Analysis > Setup 1 > right click Sweep 1 > Results > Plot Templates >

Return Loss

• Repeat the above for … > SWR

Tweaking • Tweak the values of the length and width of your patch antenna as to better match it at 10

GHz –

you

should

have

a minimum

at

approximately

10GHz

and

an

SWR

of

no

worse

than

1.3 at that frequency

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Final Plotting • Your final plots should be of Return Loss, SWR, and the Real and Imaginary parts of your

input impedance…these should all be over 201 frequencies between 8 and 12 GHz. The real

and imaginary parts of Z0 can be plotted by right clicking Results (in the Project Window)

and creating

a report…it

should

be

a standard

rectangular

plot

of

the

only

Z parameter

available – add traces for Real and Imaginary

Radiation Pattern Plotting • In the Project Window, right click Results > Create Report > Type: Far Field, Display Type:

Radiation Pattern

o Go to the Sweeps Tab, highlight the “F Point(s)” row, unclick All Values,

highlight only 10GHz

o Go to the Mag tab and select Category: Gain, Quantity: GainEThetaAccepted,

Function: dB…push

add

trace,

then

change

the

Quantity

to

GainEPhiAccepted,

add trace…click Done

o Double click the Scale on the bottom of the graph (Rho Axis Properties), change

the scaling to be from 0 to 8

• Obtain the gain at 0 degrees and the HPBW