adaptation patch antenna

hello
when I want to realize an adaptation for patch antenna with a quarter-wave line , is that the port will play the role of line 50 ohm or I must add a line of 50 ohm ?
because when i do the latter case i have a bad adaptation (-8db) and in the first case also , i dont understand , i have the good dimension , what you propose ?
thank u

Hello Abu Maria

This is what i understood from your question.
When you have a quarter wave line it has to be connected to a 50 ohm line.regardless of the length of the 50 ohm line,because impedance of the line is dependent on the width and not the length of the line.if you are well matched to the lines then you should be able to get very good response.Let me know if you need further help.i can look up your design .

Best Regards
Sajid Mohammed.

thank u sajid
please do you speak french ?

so

../imgqa/eboard/EM/EM-unvyp4xofjt.jpg

look image , i dont understund where is problem , I get bad results , sincerely I do not see what's the problem because I use directely dimensions of a thesis

i get resonance -8 db /-10db

You are welcome Abu Maria

no i dont speak french.

your diagram looks alright. except that what are the impedances of the patch? and more over did you cross check what exactly are the width's of the 50 ohm line and the quarter wave transformer.

send me your design properties i will be able to help you further.

Best Regards
Sajid Mohammed.

---------- Post added at 15:37 ---------- Previous post was at 15:30 ----------

its Quite simple when your s11 is not reasonable that means you aren't matched properly to your patch through the quarter wave transformer. and moreover check if you are using the substrate thats in the thesis . these are just speculations, bit if u can forward me the values i will be able to tell you.

thank u very much sajid

fr=2.45GHz , er=4.7 , h=1.6mm

Could you post more information as to what the size of your patch and width of the quarter wave transformer and 50 ohm line.

Abu Maria.

try these dimensions for patch,quarterwave and 50 ohm line respectively
Lp= ~29mm,Wp=37mm.
W50=3mm,L50=16.5mm.
Lq=.4mm,Wq=17.5mm

Hope that helps

Regards
Sajid Mohammed.

sadjid thank u very very much for ur help ,
I want to ask you some questions if you allow(exuse me i use google translator)
1-50 Ohm line how you find its length?
2-I find me these dimensions:
patch:Lp=27.5 mm -Wp=36.26 mm

quarter wave line: Lq=46 mm , Wq=0.16mm

in ADS momentum : I did the simulation with these two components , and the port that is given by the software momentum play the role of line 50 ohm ,dont need to design a 50 ohm line , and i obtain a good result (s11=-34 db in fr=2.4GHz) , What do you think ?

Length of the 50 ohm line is arbitrary doesnt matter if you use metre length or a centimeter length.considering the transmission line is attenuation free. i used the transmission line calculation of lambda/4.if your s11 is -34dB and you are getting good bandwidth then you should stick with this.


Hope that helps

Regards
Sajid Mohammed.

thank u very much sadjid , and very sorry for the delay in the response...
sadjid please
when i simulate single patch antenna in ads momentum ,and when I want to show the radiation pattern, and current density , it asks me to provide
1-for radiarion pattern : port excitation amplitude and phase

2-for plot current density:ads asks me to provide :solution weight and solution phase

and HONESTLY I do not know what to provide in both cases§§§§!

thank u very much freinds

Abu Maria.

Unfortunately. i have no idea how ADS works.because i never used ADS . except saw my friends using it a couple of times. i was able to help you with the dimensions of because it was very generic. i wish i could help you further,but you could always post this as a new thread.

Regards
Sajid Mohammed.

ok no problem , choukran for ur help

1- When you have a single port, like in this case, use amplitude=1 and phase=0.

2- I don't know ADS, so I doubt what means solution weight and phase. I would try weight=1 and phase=0.

I can communicate in french if you want.

à bient?t

Z

merci zorro
est ce que tu peux m'expliquer ce choix la ?
zorro
tu peux me répondre dans ce poste la , car je l'ai rouvert comme une nouvelle discussion

https://www.edaboard.com/thread235561.html

merci beaucoup.

Hi Abu,

The values (amplitude=1 and phase=0) in 1 are arbitrary. When there are several ports then the relative amplitudes and phases are important, but when there is only one, that values are the simplest.

Regards

Z


Salut Abu,

Le choix (amplitude=1 and phase=0) dans 1 est arbitraire. Quand il y a plusiers portes alors c'est important les amplitudes et phases relatives, mais quand in n'y a qu'une seule porte ces valeurs sont les plus simples.

J'ecris aussi en Anglais pou que d'autres membres puissent participer; je puex traduir s'il faut.

A+

Z