LF RFID has a long history that has proven reliable in high-water content applications and in other conditions usually not suited for tagging. Julie England, Vice President of Texas Instruments discusses how LF tags are used in various applications.

There’s been a lot of talk about whether to use UHF tags or HF frequencies when using RFID. Can you tell us about Texas Instruments’ success with low-frequency RFID?

ENGLAND: Sure, Texas Instruments has been in the RFID industry for 19 years, and it all started with low frequency RFID. One area that it’s being used on multiple continents is in livestock tracking of cattle, sheep, pigs and goats.

Another area that it’s being used is in tracking endangered species, such as the Pickering in South America. Low frequency RFID works great in harsh environments such as in the rain and around the flesh of animals, which have a very high water content.

Is it injected into the livestock in a capsule format?

ENGLAND: It can be. It’s encapsulated in hard plastic or what’s called a bolus that the animal swallows. Or, it can be placed in an ear tag or on a collar. We currently do not have a product line for implants in animals.


TI has been a pioneer, not just in the animal tracking, but also in toll road use of RFID. Do the toll roads also use low frequency RFID?

ENGLAND: Yes, TI was clearly an innovator and went to market with that entire system solution from readers to transponders and antennas. We’ve since sold that part of the business and the market has integrated into more specialties.

TI is now the third largest semi-conductor company. Over time we have become much more flexible in what we sell such as chips, packaged chips, modules, inlays, transponders, and we have continued to innovate at the semi-conductor level quite a bit.

What benefits should be taken into account when deciding whether to use low frequency RFID?

ENGLAND: First, it works well around water. It comes in many form factors. Third, it is reliable for a lifetime. Fourth, it is a low cost system design. Fifth, you can tailor the read zone to your application. And last, it has got an extremely well established global standard because of its long history.

Can you tell me more about how low-frequency RFID is used?

ENGLAND: First and foremost, TI’s low frequency duplex tags can be attached in or on any non-metallic object without any effect on its performance. Low frequency has long RF wave lengths and therefore, it is less susceptible to the effects of nearby metals and liquids. And it will allow you to read underwater. So, it has been put on fish, for example.

Now, would I be correct in saying that this is a passive non-powered tag?

ENGLAND: Yes. TI’s portfolio is a passive portfolio of low frequency, high frequency and UHF tags.

What’s the difference between half duplex and full duplex tags?

ENGLAND: Well, in full duplex, the reader and the tag are always talking back and forth to each other.

In half duplex, it looks more like a sign wave. The reader talks to the tag, then stops. Then the tag talks back to the reader, then stops. And so it is much more efficient and I would say the half-duplex records higher quality reads and writes.