Inset Feed Length,Width

[imadali]

hi everyone
I am designing rectangular patch antenna for WLANS from the equations given in balanis,but i don't know why there is some space on both sides between feed line and patch?and if it is ,then how much space,any formula,and what will be feed line Length and Width formula?
Thank you in advance

 

[mamali]

The inset is to match the antenna to the feed, different points of the patch have different impedances, depending on the mode. I suggest you to consult microstrip antenna design handbook by Garg: https://www.amazon.ca/Microstrip-Antenna-Design-Handbook-Garg/dp/0890065136; or any other microstrip antenna handbooks.