HF vs UHF: Choosing the Right Frequency

May 21, 2008 13:31 by jpeifer

With all of our customers, this is usually the first question that we need to address, “Should I use HF or UHF?” The easy answer is, of course, UHF allows for longer range, HF requires proximity. I read an article the other day about a vendor that believed this and tag price was all they really needed to know, and they are now starting to think they made the wrong choice.

In later posts we will go into more detail, but for now here is a quick overview of differences in tags and in readers. HF tags typically have a large user memory bank, memory on the tag that a user can use however they please. Certain HF tags also use secure communications protocols, protecting data as it moves between the reader and tag, and can provide anti-counterfeiting measures for high value products. But security and memory come at a price, literally, with some tags costing more than $1 per tag.

On the other end, UHF tags are almost the complete opposite. Smaller memory, usually only enough for an Electronic Product Code (EPC), no secure protocols, and long read range, all for much cheaper than HF tags. However, UHF tags with large user memory are starting to gain traction, and some tag manufacturers have started making inductive UHF tags, which have a more restricted range, but are extremely inexpensive. As a result, I wouldn’t be surprised to start seeing UHF gaining popularity in more markets.

But the story doesn’t end there. HF readers are much cheaper than UHF readers, NFC phones are becoming more popular, and contactless payment is becoming more pervasive (been to Best Buy lately?) all support for HF. So what does all this mean? In my opinion, it comes down to this: if you have many items to tag and few read points (like in a warehouse), UHF is a more logical choice, but if you have many read points in many places (such as cell phones) or you are tagging high value items, HF will be more beneficial. There are always exceptions, but this is a good start to making sure you don't end up with millions of the wrong type of tags.