Jan. 23, 2008 - Sam Liu is Director of Marketing at Intelleflex. Sam Liu has been involved in all facets of RFID

Would you explain the difference between semi-active and semi-passive RFID?

Liu: Briefly, there are generally 4 classes. Class 1 EPCgloal ratified standard for passive UHF RFID aka C1G2” ("Gen 2"). Then there are a number of proposed classifications such as Class 2 which is C1G2 with extended memory,.

Class 3 is the battery assisted passive RFID and then you have Class 4, which is active. So the Class 3 definition which we’ve referred to as battery assisted passive sometimes gets referred to as semi-passive or semi-active. But technically it’s more accurate to describe it as battery assisted passive because, unlike active, it does not actively generate a signal unless it’s being queried.

And what type of installation are you mostly using for your solutions?

Liu: To be clear, Intelleflex, even though we are developing battery assisted passive systems, we’re actually in the category of Extended Capability RFID. Which is much more than simply battery assisted passive technologies. We also do extended-memory passive system s, without the battery.

Extended memory? Could you tell me what that is?

Liu: Sure, if we look at the typical passive RFID which a lot of times is referred to as CIG2 passive which basically has a memory size of about 128 or 96 bits or less. The next level from that is to increase the size of the memory to, let’s say 64 kilobits. That can store more information on that tag but the tag itself is still passive, it does not have a battery. It uses the power from the readers.

So the extended capacity would be non-battery assisted, or traditionally it could be either.

Liu: When we talk about extended capability RFID, we’re not so much talking about a technology as much as an application. To give an example, what we focus on is not what we call commoditized passive technology aka C1G2, what we’re focusing on is extended capabilities above and beyond simply replacing bar codes or using RFID as merely a license plate.

Some examples of this extended capability RFID are multi-angled reading, being able to integrate with sensors, being able to be reliably read on challenging materials such as metal and liquid. We also do things to power RFID chips such as using it as a modem for communications to control other devices.

So would the extended capability mean that the sensors allow more data into the chips, into the IC?

Liu: What it means is that you have a way to communicate with the chip, to keep some kind of record on the tag. For example, an external temperature sensor would feed that data into the memory of that chip.

And tell me about the modem aspect.

Liu: The modem aspect is to use the chip itself as the means to communicate with an external device. Let’s say you have pricing signage at the store. You want to change the price remotely and automatically, so you can take a chip, using the IO communications from that chip to control the electronic signage. With the electronic sign, you can change the price with an RFID reader over long distances, w/o human intervention.

The modem would be in the chip or in the reader?

Liu: The chip effectively becomes a modem. It’s a way for the reader to talk to the sign through the chip. Effectively, the reader would send information through RFID, to the chip, and the chip would then communicate to the sign. So the reader is a broadcaster and the chip is a listener.

Is this commonly used?

Liu: It’s used in a number of different places, but it is an example of how companies are taking RFID capabilities and using them for multiple applications. When you start using RFID to do things you have not done before to increase your business, that’s when you realize you start to increase your business with RFID as a particle of replacement.

Is this comparable at all with the reader chips Intel is bringing out, are there different functionalities?

Liu: There are going to be different chips developed for different special functionalities. Reader chips may be optimized for readers, as opposed to a chip designed for external communications application. So you’ll see different types of chips for different types of applications. In some ways it’s another type of RF chip, and not all RF chips are the same.

What is Intelleflex most excited about this year, where do you see your applications being used?

Liu: What we get most excited about is when we see customers using our tags in their real world situations. I just came from a farm in Northern California, where this agricultural industry is using our tags to track equipment out in open space. It’s very hot in the summer time and very cold in the winter time, rain, you name it. And so seeing the technology and the products in the real world is what’s most exciting.