I subscribed to answer (shortly) to this question and because I really like reading your stories with home-made UAVs. I intend to start a small project on my own when i'll be finished with writing my PhD manuscript. But enough about me.
Remembering my antenna courses (4 years ago), the dimensions of a basic rectangular patch antenna are :
3*lambda/4 x lambda/2 or, to be clear, 0.75*lambda x 0.5*lambda, where lambda is the wavelength of your signal. In your case, f=5.8 GHz, the rectangular patch will be 38.8mm x 25.8mm.
I have to warn you that a patch antenna is pretty tough to design : especially for tuning, feeding and building it. I think you'll suffer detuning if you build it on a substrate with high relative permittivity. I'm not sure if the following formula works for patch antennas but you want to adjust the actual wavelength (awl) depending on the relative permittivity (epsilon) of your substrate :
awl = lambda * sqrt(epsilon), to be verified.
Also, the way you will feed the patch might change the radiation pattern and the input impedance, but I guess it doesn't really matter for an amateur antenna.
If you need some more information, I can have a look in my notes. Sorry I don't have the time to put it online (for now).
if not, there are many sites out there building antenna's
My favourite is FRARS they have alot of info and theory as well as practical examples such as the Short Backfire and Double Quad "Bowtie" antennas. They are all designed for 2.4GHz but a little radio theory adapts the designs to others (such as 900MHz) with ease.
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I subscribed to answer (shortly) to this question and because I really like reading your stories with home-made UAVs. I intend to start a small project on my own when i'll be finished with writing my PhD manuscript. But enough about me.
Remembering my antenna courses (4 years ago), the dimensions of a basic rectangular patch antenna are :
3*lambda/4 x lambda/2 or, to be clear, 0.75*lambda x 0.5*lambda, where lambda is the wavelength of your signal. In your case, f=5.8 GHz, the rectangular patch will be 38.8mm x 25.8mm.
I have to warn you that a patch antenna is pretty tough to design : especially for tuning, feeding and building it. I think you'll suffer detuning if you build it on a substrate with high relative permittivity. I'm not sure if the following formula works for patch antennas but you want to adjust the actual wavelength (awl) depending on the relative permittivity (epsilon) of your substrate :
awl = lambda * sqrt(epsilon), to be verified.
Also, the way you will feed the patch might change the radiation pattern and the input impedance, but I guess it doesn't really matter for an amateur antenna.
If you need some more information, I can have a look in my notes. Sorry I don't have the time to put it online (for now).
My favourite is FRARS they have alot of info and theory as well as practical examples such as the Short Backfire and Double Quad "Bowtie" antennas. They are all designed for 2.4GHz but a little radio theory adapts the designs to others (such as 900MHz) with ease.
http://www.frars.org.uk/cgi-bin/render.pl?action=link&url=99999...
Some of my successful efforts for building omni's
http://www.0wn4ge.co.uk/?page=gal&gpag=/hardware/wireless/highgain
http://www.0wn4ge.co.uk/?page=gal&gpag=/hardware/wireless/mantenna
But this design should be childs play for modellers.
http://www.instructables.com/id/10--WIFI-16dBi-Super-Antenna-Pictor...