Re: HELP PLEASE: how to find length and width of my antenna?

can any body tell me which side of this patch is its Length and which one is its Width?

Also can any body tell me the design procedure of a simple microstrip patch antenna?

In this array antenna design, you can see that the width of the transmission line is varied at different places, can any body tell me why is this happening and what effects does it have on antenna performance? Also if you can refer me a book or a website where I can know about this transmission line"s thickness variation, I will be very grateful. Thanx

Added after 2 hours 32 minutes:

Please reply to my problem

The width of the transmission lines vary to get the correct impedance matching

Dave
VK2TDN

thanx Dave. One more thing I gotta ask here, what effect does changing the position of the feed to each patch have on antenna radiation and bandwidth, or does it have effect on some other parameter? Also what is the distance between each patch equal to?, like in this case its 30mm, but is it equal to wavelength, and how? and on what parameter does this distance has its effect? Thanx

see: Microstrip antennas by Bahl
teh spacing between elements depends on design goal and line widths varying may be due to impedance matching or phase varying.

I want some more replies to my questions. Thanx

Hi,
The position of feed relative to patch effects the impedance that the transmission line will see which will effect the retrn loss and hence bandwidth that is the antenna may not resonate at the desired frequency but a little off. Anyways the position effects the impedance seen. Then the distance between the patch antennas will change the array factor hence the radiation pattern and gain. Book on microstrip patch by Pozar is good to start with. Note that as the frequency gets higher (microwave region) the mutual coupling between the patch antennas should also be taken into account.

Hope this helps

-Ankesh