Could you recommend what should I buy it?

I’m planning to make a tracking system just in a small hollow sphere space.
It is just 13cm diameter so there can be need a rfid tag and a few of antennas.
But I don’t know what should I buy it…
So,could you recommend x-series that read range can be about 12cm and an antenna please??

Thank you.

Does router works instead of Antenna?

umm… my plan is antennas are connected in rfid reader and it can calculate distance so that it can find location.
And I just wounder x-series’s range can be about 10cm.
Because tag is too small…
Beside, my project didn’t allow rfid tag’s size over 4diameter.

Passive RFID tags are magnetically coupled devices… how are you planning to calculate distance?