Ok... the question of UHF vs. HF for item level RFID tagging is bigger than Beta vs.VHS or for the younger people Blue-ray vs. HD-DVD.  This is an all out war between the established HF companies and the new up-and-coming UHF companies.  There is so much propaganda out there it is difficult to determine fact from fiction or truths from half truths. In order to compare these two technologies it would be fair to state that I will discuss near field UHF not far field UHF.  Some of the HF folks like to compare HF to far field UHF to tilt the playing field in HF's favor

I am actually going to start with discussing the cost of making each type of RFID tag.  If history teaches us anything is that the low cost producer usually wins all else being equal.  Assuming the performance of both HF & UHF tags are the same (I will discuss and contrast performance in the next few posts) then tag costs will determine the winner. 

HF Tags 2 layers of many turns of etched copper.  This is expensive to manufacture (look at all the copper!) - actual size of the tag 12mm
UHF Tags 1 layer and can use conductive inks (very simple looking - that is a good thing!) - actual size of the tag is 9mm

I also look at the large companies that would have an impact on pushing the decision to UHF or HF.  Wal-Mart has already committed to UHF far field for case and pallet tagging.  So I would summarize that Wal-Mart would not want to have two different  RFID technologies.

Also the major distributors; Cardinal, McKesson and ABC have come out in favor of near field UHF. 

Back to the question at hand..."UHF vs. HF" for item level RFID tagging?  If I was a betting man there are several reasons why I would pick near field UHF to become the item level tagging standard:
1. UHF is much easier to manufacture
2. Simple antenna geometries
3. Inexpensive conductive ink process

All else being equal the low cost producer wins.  In this case UHF would seem to be the logical choice. 

Stay tunned for more posts about RFID hardware and deployments costs and I will contrast performance issues between these two competing technologies.