microstrip line fed patch antenna

[shahid78]

inset microstrip line

hi

i was wondering if i feed my patch antenna by microstrip line using quarter wave transformer.

how should i find the edge input impedance of the patch which is needed to calculate the characteristic impedance of for the quarter wave transformer.
also we will be connecting this quarte wave section of line with 50 ohm microstrip line for feeding the patch through 50 port.
now i am wondering is the lenght of the 50 ohm secttion of feeding line has any signifance or we can use any length.

also is the length of the quarter wave section needs to be optimized or the lambda/4 is good enough for matching

i will apreciate any comments on this

regards

 

[shameemkabir]

hi

i was wondering if i feed my patch antenna by microstrip line using quarter wave transformer.

ya, possible. Just out of curiosity: why don't you consider an inset feed so that no quarter wave transformer is needed?

how should i find the edge input impedance of the patch which is needed to calculate the characteristic impedance of for the quarter wave transformer.

Put a port at the location where you want to match with quarter wave transformer. Simulate the structure and take a look at the the smith chart from where you can find the port impedance. then calculate your required characteristic impedance of the quarter wave transformer.

now i am wondering is the lenght of the 50 ohm secttion of feeding line has any signifance or we can use any length.

length of 50 ohm line is not very crucial.

also is the length of the quarter wave section needs to be optimized or the lambda/4 is good enough for matching

lambda/4 is good enough for matching.

 

[shahid78]

hi shameem

well thanks for your reply to my post
well as i mentioned in my previous email i know about the inset feed but i was trying to learn about quarterwave transformer matching


well you said put the port at the location at which i want to match . do u mean right at the edge of port?becuase thats the point at which i will be putting quarterwave transformer


thanks for your comments

regards

 

[shameemkabir]

hi shameem

well you said put the port at the location at which i want to match . do u mean right at the edge of port?becuase thats the point at which i will be putting quarterwave transformer

yes. However, if you simulate with HFSS, I'm not quite sure whether you can set the port at that location. If you have access to ADS momentum or CST MWS, you can put a lumped port and simulate the structure to get the impedance.

regards,
Shameem