What would be the general time from reader antenna to chip, and from chip to antenna? Which are the best readers, and what chips respond the most quickly? And what chip requires the least activation time, if parameters like that exist?
The amount of time that it takes for an RFID reader to send a signal to a tag varies, depending on the type of RFID tag (LF, HF, UHF or active RFID). It depends on the distance from the tag to the reader and the environment in which that tag is being read. If there is interference or multipathing, for example, that will slow down the read speed.
Typically, it takes a few milliseconds for a passive UHF tag and a reader to communicate. I have witnessed 50 tags being read so quickly that it appeared they were all being interrogated simultaneously, when the reader was actually communicating with each one individually and effectively.
Virtually all passive UHF tags have a high read speed. So if you were to purchase any models of readers and tags from any well-known passive UHF RFID hardware providers, you would be able to achieve high read speeds.
—Mark Roberti, Founder and Editor, RFID Journal