Microstrip Antenna with coaxial feed

Dear Friends,

I am studying the patch antennas . I am confused by the coaxial feed type, here is my questions and thank you very much for answering.

1, how can I locate the feed point? Is the distance from edge calculated as the same way as the inset feed?

2, can I treat the coaxial line as the input impedence? Is the lenght of the line determined by the antenna?

I appreciate your answers[/b]

hi
can any one help me?

T^T
HELP...

which type of patch antenna u r planning to design?

rectangular patch antenna， coaxial feed.

Added after 5 minutes:

built it and simulated!

but I want to put a waveguide to cover it enable the radiowave travelled inside the waveguide and see the energy propagation.

Could you recommend some references?

Thanks