Designing compact microstrip patch antenna at 868MHz , on Fr4 of 4,4 and height of 1 mm

[HC12]

Hi , i amtrying to design a mivrostrip antenna sensor that can atract tempretur on left side .
The frequency is 868 Mghz , the material is FR4 of 4,4 and 1 mm height .
I have to designe it pn FreeCAD , than export it to open ems .
I started whith the Idea of a patch antenna , but it was very big ,it had 105,17mm width and 82,3mm length .
So i thought of a microstrip meandered dipol antenna . But i didnt found any formula for geometrie calculations . And i don't find enaugh resource for FreeCAD simulation .

Do any one have idea about formula for calculation for meandered dipol microstrip antenna.
Thank you so much

 

[volker@muehlhaus]

Have a look at these Texas Instruments application notes:
Design Note DN023
Design Note DN024

The size of ground plane matters and will change resonance frequency, so some tweaking of radiator length will be required. You can simulate that in OpenEMS.