# Please Take a look at 900Mhz Patch antenna!

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##### Junior Member level 3
This is the 900Mhz antenna we have designed by consulting Balanis's antenna theory book but the dip is way off the 900Mhz freq that we want. Can some one please check this and tell us the error we are making?

#### Attachments

• 900_error.rar
8 KB · Views: 15

#### WimRFP

Hello,

Maybe you can post an image with size reference, relative permittivity, etc. This enables more people to answer your question.

#### rotmanlens

##### Banned
starting to run your design.first thing that was noticed was the simulation didn't converge. antennas is not well matched to 50 ohm. waveport instead of lump port. will pst your file here after the simulation are finalized

Best regards
Sajid Mohammed.

Points: 2

##### Junior Member level 3
Sir Sajid I will be very thankful for your favour.

Sir this antenna has matching issues, I have optimized it a lot but cannot seem to get it right. I have been optimizing its inset distance Yo but no success so far.

#### rotmanlens

##### Banned

I have worked on your patch and set the values,i can copy the values here if you would like. the size of the patch and length were changed to get resonance along with the inset point and there was good resonance at that frequency .Unfortunately the gain is not upto par.because of the FR4 substrate.

Best Regards
Sajid Mohammed.

Points: 2

##### Junior Member level 3
Sir Sajid kindly post the modified design or values here so that all can benefit from it as I was in much difficulty to get this right. Sir I need a range of hardly 6-10 meters so I think that even less gain will do the job for me.

Regards

#### rotmanlens

##### Banned
everything stayed the same except i just changed the size of the patch i.e $L,$W and $farz$w0 are here respectively 68, 162,123.57,3.05

Hope that helps

Regards
Sajid Mohammed.

Points: 2

##### Junior Member level 3
Sir Sajid are these values accurate?

Length of Patch=68
Width of Patch=162
Wo=3.05

#### rotmanlens

##### Banned
yes these are the values

Regards
Sajid Mohammed.

Points: 2

##### Junior Member level 3
Sir this is giving a Dip at some where before 860Mhz where as I want a dip at 900Mhz. Sir what freq are u getting the dip at?

#### rotmanlens

##### Banned
the dip is around 910mhz. but shorter the width of the patch you will find the patch resonanting at correct frequency. i did tuning of the patch may be the patch width was not precise but it is still closer to the frequency of operation thanbefore.try shortening it a little bit and see the exact resonance

Regards
Sajid Mohammed.

Points: 2

##### Junior Member level 3
ok Sir, Thanks a lot

#### rotmanlens

##### Banned

Hope you have a better insight into your project

Regards
Sajid Mohammed.