Dual frequency antenna

I would like to know if someone has an idea about how to design a dual frequency microstrip patch antenna feeded by a microstrip line? the two frequncies are two close 600 and 630 MHz. This antenna must be compact ( 80 * 80 mm2)

you can try a hollow patch antenna, unfortunatelly i dont have any tutorials but there are some papers i think you can use.

Added after 8 minutes:

Thanks a lot.you are so kind

Hi Pabloec,

do u have somethin' about stacked patch antenna? I need layer and structure dimensioning...

Excitation by probe...

Thanks in advance,

Lupin

Hi helio1972,

Why don't you try fractal MSA? It is possible to obtain dual-frequency operation with the feature of miniaturization. The length of current path plays a role in this matter.

rgds,

Added after 3 minutes:

Hi Lupin,

Have you read this paper?

https://www.edaboard.com/viewtopic.php?p=323954#323954

rgds,

In which topic can I find it?

I need a proper dimensioning of a stacked patch in order to have a broadband mode...

What gain can I expect to find? I think 12-14 dBi.. what do u think?

Regards,

Lupin

Hi Lupin,

You can take a look at the paper entitled "Broad-band dual-frequency microstrip patch antenna with modified Sierpinski fractal geometry". This is all about the stacked modified Sierpinski gasket excited by a coaxial probe. The gain observed at the both frequencies are around 6.0 and 7.0 dBi.

rgds,