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how can i adjust the resonance frequency of the printed dipole ?

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blueray

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Hi all

i am working on printed ellipse dipole antenna which s working on 900 Mhz . But i have some boundaries the lenght of the dipole must be max 72 mm. i have simulated on HFSS but i cant see a good returm loss for this . i have -2 or -3 db return loss on 900 Mhz .So how can i decrease the rezonance frequency without increasing the lenght of the dipole ?

thanks for your helping
 

Can you post a picture of your elliptical dipole ?

Given operating frequency of 900 MHz, the total length restriction you place on it is about 0.21*lambda. Dipoles are generally of the size ~0.48*lambda.

Electrically small antennas (ESA) should be possible, but do post a picture of what you are trying, so that we can provide more information.
 

you can base load the antenna elements with series inductors (one per arm), or you could add capacitive patches at the open ends.
 

blueray said:
Hi all

i am working on printed ellipse dipole antenna which s working on 900 Mhz . But i have some boundaries the lenght of the dipole must be max 72 mm. i have simulated on HFSS but i cant see a good returm loss for this . i have -2 or -3 db return loss on 900 Mhz .So how can i decrease the rezonance frequency without increasing the lenght of the dipole ?

thanks for your helping
Click to expand...

With out more info all answers/suggestions a based on assumptions !

So if you have this antenna on a PCB you can changes the εr to a higher number. This will reduce the
length of λ so with the same real estate you will have a lower resonate frequency .

If you double your εr of the PCB that will make the same length trace resonate at an Fo of ~30% lower.
Play with this app.
https://www.rfcafe.com/references/calculators/wavelength-frequency-calculator.htm
Cheers
 
**broken link removed**

thanks for all of you

in the given picture i have a ellipse on top side and elllipse on bottom side now . next level i will add a tapered balun bottom side .

actually i try to do it in 900 - 2200 Mhz wide band and because of some boundaries my antenna should be max 72 mm and the ratio of ellipse should be 1.4 or 1.2 . i know it if i increase the length rezonance frequency decrease but i cant increase the length i should find another way.

@Element_115

thanks for your answer

my antenna will be PCB and we have rogers4003 substrate and its dielectric constant is 3.55.
 

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your attachment link doesnt work

attach the image so it shows within your post :)

Dave
 

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