I would like to make a two-in-one reader combining passive high-frequency (HF) and ultrahigh-frequency (UHF) RFID technologies. If this is possible, what would be the best way to go about doing so, and what are the biggest challenges I would face?
The answer would depend on what you mean by "connect." It is possible to put a passive HF and a passive UHF reader in the same box and have the data from each flow into a single CPU in the box for filtering purposes, and to have the information passed on to a back-end system via a single Ethernet or Wi-Fi connection. However, it is not possible to connect a passive HF antenna to a UHF reader, or vice versa, and have the same reader interrogate passive HF and UHF tags. The air-interface protocols used for each are different, so you would need two separate reader chips, even if they were on the same circuit board or in the same box.
Tagsys RFID used to offer a dual-frequency RFID reader (see Tagsys Debuts HF/UHF Reader for Retailers), as did ThingMagic and iPico Holdings (see New Two-Frequency RFID System) at one time. GAO RFID offers a reader that operates in both the LF and HF bands, and STiD offers a similar device.
—Mark Roberti, Founder and Editor, RFID Journal