Feed point - microstrip patch antenna

feed point microstrip

How to determine the feed point location for a rectangular microstrip patch antenna.. Fed by microstrip linefeed.

Does it depend on substrate thickness, dielectric constant etc ?

Hi, sumit007:

Yes. It is affected by Er, Thickness (T) of the substrate, and width (W) of the patch antenna. Normally, Zin does not change much in the non-resonanting direction. It changes from slightly above 0 to about 250 ohms from the center to the edge when the location is changing in the resonating direction. The curve is dependent upon the Er, T and W. When W is bigger, the line between the X = 0 and X = L/2 is closer to a straight line. When W is small, the R will be increasing from 0 slowly and it will go to high value when it is close to the edge.


L
-------------------------
| |
| W -> | -> resonating direction
| |
------------------------ -> x

Best regards,

Hi, sumit007,

you may want to get hold of this book, Antenna theory analysis n design. It is a very good book. Inside contain the equation for you to calculate the feed point.
good luck

Hi, sumit007
this good book:Compact and Broadband Microstrip Antennas,it can help you solve the problem!
good luck!