 Okay so welcome to another short tutorial on SD25 NFC channel. I have noticed recently that I actually don't even have an NFC antenna design segment on this channel and I remember I've done it a while back on a different channel but since all the videos are now on this particular channel I'm just like to do a quick reboot on NFC design NFC antenna design so if you go on to www.sd.com navigate to e-design suite and go to RF design then click on NFC antenna design once you arrive at the NFC inductance screen you notice that you are given a bunch of different parameters that that you can design your antennas so in this case in the particular default values you will have the inductance of 1.5 micro Henry but since we are talking about different antenna structures in different application for example if you are using SD25 DV it uses a chip's capacitance of about 28 29 picofarad and that's translate to 4.7 micro Henry if you want to have a resonance at 13.56 megahertz so in that particular application you would want to be beyond the 1.5 micro Henry that that is as a default values so here you could increase the number of turn say let's do 5 turn and here you see that the inductance has already increased so now if you go to 6 turn it's at 4.52 and if you go to 7 now it get a little bit too high in this point you are beyond the 4.7 micro Henry and needed for the SD25 DV dynamic tag I see so you need to reduce your number of turn to 6 and another rule to come by is that you sometimes want to be below the 4.7 micro Henry so even 4.5 4.6 it's good enough in many ways because you can add a small parallel capacitor to the chip capacitance and that will change the that allow you to tune the resonant frequency but if it is 4.8 which is too high you cannot shave away capacitance from the chip so it's better to be slightly lower than the 4.7 micro Henry so certainly you can start with a different I would say dimension of the antenna so you want a 50 by 50 square antenna and in this case the antenna will be smaller and you will have different metric and you can change the conductors value as well the width of the trace on your layout say it would change to 0.5 and you can see some deviation as you change that substrate you can also change that as well now remember that this antenna design software does not accept a two layer antenna so it will be a straight single layer antenna now if you are designing antennas for our SD25 or readers and as you know for tuning purposes we would not go beyond 2 micro Henry but not so much lower than 500 nano Henry or so you can use the same application to design antenna for our reader transceiver ICs as well so there you go the NFC inductance can be calculated and the antenna geometry can be shown and you can use the measurement and implement that on your layout software unfortunately at this time we do not have output in Gerber's hopefully that could change in the futures but at least using this metric you can design your rectangular or square antennas quite easily thank you