input impedance antenna p(at)tch

EDAboard.com Forum Index -> RF, Microwave, Antennas and Optics -> input impedance antenna p(at)tch

Author

Message

max232

Joined: 20 Dec 2002
Posts: 588
Helped: 33

26 Mar 2004 0:41 input impedance antenna p(at)tch

Hi

The input impedance at the leading radiating edge of p(at)tch is known .
I wish to feed it with a line to have input impedance 50 Ohm,
I found the length of this line,

But which is that width Embarassed

Regards

goxy

Joined: 25 Jul 2002
Posts: 268
Helped: 1

26 Mar 2004 12:36 Re: input impedance antenna p(at)tch

Use some calculator, for example http://www.appwave.com/products/txline.html .

max232

Joined: 20 Dec 2002
Posts: 588
Helped: 33

26 Mar 2004 13:25 Re: input impedance antenna p(at)tch

hi

thak you goxy .

I cannot download this software, I believe that it is similar with ansoft desing (it can make me this kind of calculates).

My problem it is transferred the input impedance of an antenna patch (Rin) at a distance Y0 that to have 50 ohms.

The formula is : Rin(Y=Y0) = Rin(Y= 0) (cos (pi * Y0/L))^2.

It remains me to calculate the width (w0) of y0.

But I do not know the impedance characteristic ( Zc )of this line (Y0 ) .

Regards

VSWR

Joined: 07 Feb 2002
Posts: 767
Helped: 72

26 Mar 2004 15:50 Re: input impedance antenna p(at)tch

Are you trying to match the antenna's input impedance to 50 ohms? Via a piece of microstrip conductor? And you would like to know it's width?

As it seems you're using Ansoft Designer, it would be easy to do this using this program.

Zip and upload your design files here so we can take a close look (to see what substrate you're using, etc).

Google
AdSense
Google Adsense

26 Mar 2004 15:50 Ads

max232

Joined: 20 Dec 2002
Posts: 588
Helped: 33

26 Mar 2004 16:11 Re: input impedance antenna p(at)tch

I start to learn with ansoft design, on this software I draw my patch and the feeder line. I calculated the width theoretically and the length of the rectangular patch et also the length of the line matching 50ohm , on ansoft desing, I can given only the length and the width of the patch by estimate.
I give you the information of my patch.

Substrat FR4 Er=4.32
H =1.52mm
Fr = 2 Ghz

After theoretical calculation I found:

W = 4.5985 cm
L = 3.5789 cm
R in du patch =444.4247
Y0 = 1.3998 cm

Regards

max232

Joined: 20 Dec 2002
Posts: 588
Helped: 33

26 Mar 2004 16:56 Re: input impedance antenna p(at)tch

GaAs FET wrote:

Zip and upload your design files here so we can take a close look (to see what substrate you're using, etc).

I fixed W0 of the feed line of p(at)tch 1mm

Sorry, but you need login in to view this attachment

yuppi77

Joined: 18 Dec 2003
Posts: 33

26 Mar 2004 17:12 Re: input impedance antenna p(at)tch

max232 wrote:

Regards

Hi,

First of all, you need to know what is the dielectric you are using & the tangent loss, following that you could use calulate the width of the line.

If you know the impedance of the radiating edge and you wish to feed it with a line with 50 ohm, you could use a impedance transformer in between these 2 lines.

Hope this information is what you need.

Thanks.

IICCEE

Joined: 24 Dec 2001
Posts: 233
Helped: 2

27 Mar 2004 18:00 input impedance antenna p(at)tch

the impedance can be derive from the plannar circuit model. REF: Gilnini paper.

max232

Joined: 20 Dec 2002
Posts: 588
Helped: 33

27 Mar 2004 23:47 Re: input impedance antenna p(at)tch

IICCEE wrote:

the impedance can be derive from the plannar circuit model. REF: Gilnini paper.

.

You can give me the title and the date of paper .

#If I fix the impedance characteristic of the line exp: 100 Ohm , I believe that I can have w0 Embarassed

#

Thank you

goxy

Joined: 25 Jul 2002
Posts: 268
Helped: 1

28 Mar 2004 17:09 Re: input impedance antenna p(at)tch

Chack again, here you direct link http://www.appwave.com/src/products/TXLine.zip

You no need calculate distance, only line width bacause we make waveguide and because we have constant imedance.
So, if your antenna have 100ohm impedance you know line with, if you need 50ohm impedance you also know line width. Just conect this lines and that's all.

zfl

Joined: 05 Mar 2004
Posts: 22

29 Mar 2004 5:12 Re: input impedance antenna p(at)tch

Hi,the input impedance at the leading radiating edge of p(at)tch is known?isn't 100or 50 or other ? if it isn't 50 ,you would use a transformer!and the impedace value must right!

zfl

Joined: 05 Mar 2004
Posts: 22

29 Mar 2004 5:16 Re: input impedance antenna p(at)tch

Oh,why not coaxial probe? If so, it will very be easy! Good luck!!

max232

Joined: 20 Dec 2002
Posts: 588
Helped: 33

30 Mar 2004 15:55 Re: input impedance antenna p(at)tch

I did not manage to match my patch at 50Ohm Sad

max232

Joined: 20 Dec 2002
Posts: 588
Helped: 33

01 Apr 2004 17:43 Re: input impedance antenna p(at)tch

hi

somebody can help me to find the dimensioning of my p(at)tch with the line microstrip feed .

er 4.32
Fr 2Ghz
H =1.52 mm

thank you

Sorry, but you need login in to view this attachment

VSWR

Joined: 07 Feb 2002
Posts: 767
Helped: 72

02 Apr 2004 9:52 Re: input impedance antenna p(at)tch

Dimensions are missing:

LPatch = ? mm
WPatch = ? mm
WSlot = ? mm
Lfeed = ? mm
Wfeed = ? mm
LSlot = ? mm

max232

Joined: 20 Dec 2002
Posts: 588
Helped: 33

02 Apr 2004 11:28 Re: input impedance antenna p(at)tch

Hi

It 's that my major problem ,I did not find all the dimentions .

LPatch = 35.789 mm
WPatch = 45.985 mm
LSlot = 13.998 mm

I can found WSlot ,Lfeed ,Wfeed

Regards

abdoeng

Joined: 22 Feb 2004
Posts: 685
Helped: 14
Location: EGYPT

02 Apr 2004 22:32 Re: input impedance antenna p(at)tch

hi max.232,an iteration method is to move the small width t.l. left and right,untill reashing ur 50 ohm impedance or move into patch untill desired 50 ohm obtain
regards

eirp

Joined: 11 Dec 2001
Posts: 639
Helped: 9
Location: Phase center

02 Apr 2004 23:06 Re: input impedance antenna p(at)tch

Hi, max!

Why you simply don't perform an optimization (for example in IE3D?)??
Your project has a low degree of freedom, you'll get answer quickly!!

Regards,

eirp