The patent for the RFID chip technology is owned by multiple companies, research agencies, and universities.
To list a few, a patent for the RFID chip technology is owned by the Massachusetts Institute of Technology (MIT). Their patent was "Issued July 11, 1995 for invented by Gregory D. Abrams" which covers a technology called Selective Compliance Assembly Robot Arm or SCARA (U.S. Patent No. 5,471,499).
Texas Instruments also owns a patent in this domain. They acquired Impinj, a company specialized in radio-frequency identification (RFID) solutions, in 2019 and the patent portfolio included in the acquirement gives Texas Instruments the RFID chip technology patent.
NXP Semiconductor owns a patent that covers the RFID chip technology. This patent is called “Method and apparatus for using a radio frequency identification system to maintain item attributes” which was granted on May 20, 1997 (U.S. Patent No. 5,639,252).
Thus, these are only a few of the companies, research agencies, and universities that own the patent for the RFID chip technology. Further research into the various patents and associated parties is required for more information.