Hi
I'm designing a new product with 2 layers, 1mm PCB, FR4, 1oz copper and a TX 433MHz PCB Antenna, we already use a very common model from the internet in our products (Application Note 52 - MICREL) and works fine, but learning more about RF i founded some things:
1: For 433MHz you should use the 1/4 wave length rule witch gives 17,3cm length antenna, the antenna from N52 have 18,6cm counting all vias with a 1.6mm board.
2: Altium have a field solver so putting the data it will give you the width trace for impedance matching. The antenna model uses a trace width of 1mm but altium gives a width of 1.6mm (50 ohms 1% precision) on "single type" and 0.411mm for "single coplanar type" on the balun part.
Images: 1: My layout with 0.411mm trace Balun part with stiching vias
2: My Layer Stack Manager with the inputs
My 3 questions are:
I should correct the length of model antenna to match the 17,3cm for boards with 1mm and 1.6mm to improve performance?
I founded wierd that the model uses 1mm width for the antenna instead of 1.6mm which altium calculates for type single to reach the 50ohms, is this antenna model right?
I inserted the pcb values (you can se all on the stack layer manager image) on 2 websites and they give a width of 0.55 and 0.7 mm instead of 0.411? which one i should trust?
The 2 websites: https://spok.ca/index.php/resources/tools/99-cpwcalc
https://wcalc.sourceforge.net/cgi-bin/coplanar
Images: 3: One site calculates 0.55mm
4: Other site calculates 0.7mm
I'm designing a new product with 2 layers, 1mm PCB, FR4, 1oz copper and a TX 433MHz PCB Antenna, we already use a very common model from the internet in our products (Application Note 52 - MICREL) and works fine, but learning more about RF i founded some things:
1: For 433MHz you should use the 1/4 wave length rule witch gives 17,3cm length antenna, the antenna from N52 have 18,6cm counting all vias with a 1.6mm board.
2: Altium have a field solver so putting the data it will give you the width trace for impedance matching. The antenna model uses a trace width of 1mm but altium gives a width of 1.6mm (50 ohms 1% precision) on "single type" and 0.411mm for "single coplanar type" on the balun part.
Images: 1: My layout with 0.411mm trace Balun part with stiching vias
2: My Layer Stack Manager with the inputs
My 3 questions are:
I should correct the length of model antenna to match the 17,3cm for boards with 1mm and 1.6mm to improve performance?
I founded wierd that the model uses 1mm width for the antenna instead of 1.6mm which altium calculates for type single to reach the 50ohms, is this antenna model right?
I inserted the pcb values (you can se all on the stack layer manager image) on 2 websites and they give a width of 0.55 and 0.7 mm instead of 0.411? which one i should trust?
The 2 websites: https://spok.ca/index.php/resources/tools/99-cpwcalc
https://wcalc.sourceforge.net/cgi-bin/coplanar
Images: 3: One site calculates 0.55mm
4: Other site calculates 0.7mm
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