who can help me about dual-band slotted microstrip antenna?

Now, I am designing a dual-band slotted microstrip antenna, however, I can't get satisfying results. what are the equivalent modes of an L or U slotted or slitted microstrip antenna? what are the slots effect? Can anyone help me? Any suggestion will help me a lot, Thanks!

The effect of a U-slot in a p atch antenna has been tested by K.F. Lee in 1995...In probe-fed p atch antennas the U-slot adds an inductive reactance that compensates the capacitive behavior of the probe feed (improving the impedance matching)...

See these papers for more details:

https://www.edaboard.com/viewtopic.php?t=97124

Design guidelines for applying the U-slot to patch antennas has been provided in:

Analysis and design of broad-band single-layer rectangular U-slot microstrip patch antennas
Weigand, S.; Huff, G.H.; Pan, K.H.; Bernhard, J.T.;
Antennas and Propagation, IEEE Transactions on , Volume: 51 , Issue: 3 , March 2003
Pages:457 - 468

You can find this article attached below...

Hope this helps :)
mogwai...

Hi

try this

http://www.mcu.cz/atm/index.php?&dir...Francois%20pdf

PL