Systems and techniques to assemble RFID tag can be employed in a manufacturing endeavor. An RFID tag assembling system includes an RFID module conveyor that moves a first substrate having multiple RFID modules, an RFID antenna conveyor that moves a second substrate having multiple RFID antennas with respect to and into alignment with the first substrate, and a joiner in proximity to the first substrate to separate the RFID modules from the first substrate and attach the RFID modules to the RFID antennas on the second substrate. The substrates can be reel-form substrates, and RFID tags can be formed in parallel. The system can also include an RFID module tester, and the RFID modules can be tested in parallel.