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# microstrip patch antenna design

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##### Newbie level 2
i wanna design a microstrip patch antenna with following specifications
Patch:-
Length=35.014mm
Width=45.33mm
Transmission line:-
length=20.392mm
width=2.911
Frequency band:-
1.930-1.990Ghz
with center frequency at 1.960Ghz

but now m unable to understand electrical length n characteristic impedence of line in degrees...
i dont know what does these terms mean?
kindly do help me...

#### g86

##### Full Member level 4
Electrical lengths can be expressed in terms of wavelengths. Line lengths can add phase shifts and be expressed in terms of degrees. For example quarter wavelength is λ/4 ≡ 90°.

Points: 2

### ehab esam

Points: 2

#### sevcan26

##### Newbie level 3
hi
which program you use to design such a patch antenna?

##### Newbie level 2
hi dear!
thanx a lot for ur concern.
m using HFSS for designing...
actually am not confirm whether i should make a quarter wavelength antenna or not.
what if i dont know the dimensions of transmission line?
the only thing i know are the dimensions of patch which i already narrated.

#### Element_115

You have to know what is the Dielectric of the material you are using to
get λ εr = ?.

If you put those dimensions listed on a PCB w/ εr = 4.3 it might be good,
but if your PCB has an εr = 9 it might be way off.

Look for APPCAD or go to Rogers PCB website and look for a free web
transmission line calculator.

That should get you started in the right direction.

Cheers

#### gazi099

##### Newbie level 2
Sorry i have a similar question ...

A microstrip patch antenna for WiMAX system operates at 2.5 GHz. The Substrate is RT/Duroid 5880 (εr=2.2) with a thickness of 0.508 mm. The antenna is fed by a
50 Ω microstrip line, and a quater wavelength transformer is used for the impedance matching.

a) determine the physical dimensions (width-W and length-L) of a rectangular microstrip patch antenna.

b) determine the physical dimensions (width-W1 and W2 and length-L1) of a rectangular microstrip patch antenna.

c) simulate the antenna circuit using the em sonnet/ADS software package and plot the input return loss from 1 to 4 GHz

d) create a layput of the antenna circuit using ADS software package....

I have solved par a) and the answers are:

L=40.24 mm
W=47.40 mm
Z0=125 Ω or 144 Ω

Now can anyone help me out with the next bits I mean the other W1 and W2 and L1 and also recomend a easy online or small software...

antenna looks like this

from fig λ/4 is L1 HOW DO I CALCULATE THIS
and the width of the other portions W1 and W2

pdckgm

### pdckgm

Points: 2

#### jmga9

##### Junior Member level 2
Hi,
i´m doing a microstrip antenna to operate in 2.42GHz.
The substrate has: thickness: 1.6mm; Er=5.
The dimensions are 27.2x54.4 mm.
The input impedance is 281.25 ohms. My questions are:

- I have to do a 50 ohm line, followed by a quater wavelength transformer and then the antenna?
- And about the ground plane? must have specific dimensions?

Thnks,

jmga9

#### doylay

##### Newbie level 1
i wanna design a microstrip patch antenna with following specifications
Patch:-
Length=35.014mm
Width=45.33mm
Transmission line:-
length=20.392mm
width=2.911
Frequency band:-
1.930-1.990Ghz
with center frequency at 1.960Ghz

but now m unable to understand electrical length n characteristic impedence of line in degrees...
i dont know what does these terms mean?
kindly do help me...

hy mirza, may i ask you?
how can u find the transmission line lenght n width?
can u give me the formula?
and one more,
are u indonesian?

#### ihamieh

##### Member level 1
hello Mirza,
I'm a graduate student and I'm working on designing something similar but with different parameters using HFSS. I'm doing a 77GHz patch antenna with inset fed! I'm thinking about doing an array for this antenna! Do you know a formula that we can use to define the array and stuff?? I'm kinda a newbie to this field and I'm trying my best!
Any help is greatly appreciated.
Thanks
Ish

i wanna design a microstrip patch antenna with following specifications
Patch:-
Length=35.014mm
Width=45.33mm
Transmission line:-
length=20.392mm
width=2.911
Frequency band:-
1.930-1.990Ghz
with center frequency at 1.960Ghz

but now m unable to understand electrical length n characteristic impedence of line in degrees...
i dont know what does these terms mean?
kindly do help me...

#### Azulykit

This reference may be helpful and it includes software.

"CAD for Microstrip Antennas" by Dr. Saintani.

It is often hard to find but copies are sometimes posted.

ihamieh

### ihamieh

Points: 2

#### ihamieh

##### Member level 1
hello Azulykit,

I couldn't find this book but I found a site about Dr. Saintani...

Do you have any HFSS manual that instructs you to do an inset fed patch antenna? I found one for coax fed and not inset!!!! Like I said I'm kinda new to this field... Any help is greatly appreciated..

Thanks,

This reference may be helpful and it includes software.

"CAD for Microstrip Antennas" by Dr. Saintani.

It is often hard to find but copies are sometimes posted.

#### Azulykit

As I recall I tripped over the book on
Code:
Rapidshare
. You might poke around there to see if you can find it. Files come and go there.

An inset feed is essentially a microstrip feeding the edge of a patch antenna. Think of a notch cut in the patch and the microstrip attaching at the bottom of the notch. The impedance may be adjusted with the depth of the notch. Typically one feeds a patch with a 50 Ohm line and to match it the feed point in inset (about 20% of the width as a WAG) to match to the feed line. You will often see this structure in the literature as it is a common trick.

#### vaishali sagar

##### Newbie level 6
hello,
i need help in calculating the dimensions of patch antenna.the calculator for microstrip line in emtalk asks for "elctrical length in degrees" and i am not able to calculate.
can anybody help me for the dimensions of rectangular patch antenna at
freq = 2.25 GHz
dielectic const = 2.2
thickness = 0.508 mm

##### Newbie level 6
hi,

i am interested to know how you design feeds on radiating and non radiating edges for rectangular patch in HFSS.....e.g. the figure you have mentioned above, can u guide how u did it in HFSS?

thanks

---------- Post added at 12:49 ---------- Previous post was at 12:44 ----------

hi ,

I found a related tutorial on emtalk. It is at em: talk - HFSS Tutorial 1: Microstrip Patch Antenna

but unfortunately i am being unable to access it and i also dont find anyplace to signup

does anyone one know how to access it?...thanks

#### vaishali sagar

##### Newbie level 6
hey,
you need not sign up at em talk.It is accessible and i simulated a rectangular patch with the following dimensions and it worked.
freq=2.25 GHz
electrical length = 180 deg
height of sub = 3.2 mm
ground coordinates = 171.14,180.7,0
feed dimensions = 45.6 , 9.85 , 0.5

em: talk - Microstrip Patch Antenna Calculator
Microstrip Line Calculator | em: talk

the second link is for the strip line and the first is for the patch.give it a try
all the best

##### Newbie level 5
i need design for circular polarization microstrip antenna in frequency 435 MHz and 145 MHz , it's independent antenna not dualband antenna,, any want to hepl me,, please,,

#### Tuan Rahmand

##### Newbie level 2
Does anyone know how to calculate the ground plane ?
and how to find the coordinat in HFSS ?

Thanks

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