Learn how preliminary testing will help you fast and cost effectively assess whether RFID technology is a good fit for your battery-free sensing needs.
RFID technology can be complex to evaluate. The fact that these solutions work on a limited energy budget and it involves wireless communication makes it more complicated than just having a look at a datasheet or a bunch of specifications.
In general, RFID technology based solutions will be dependent on the real application environment. The fact that a standard solution does not work properly in your environment does not mean the RFID technology is not a good fit.
There are three levels at which RFID technology assessment may be done:
This is unlikely your case, but as an RFID IC manufacturer you want to check the performance of your chips and compare with the simulations resulting from the design phase.
There are multiple tests you want to run – i.e.: on wafer, bare die or packaged. For simplicity, we’ll just talk about packaged IC here.
To use a real case, we’ll use our own experience in RFID IC manufacturing. We are currently working on a new version of tag IC for battery-free sensors with enhanced capabilities. After the new RFID chip for battery-free sensor has been manufactured, first prototypes are run. Initial testing will require a PCB with circuitry to allow us to monitor the key parameters of the chip.
This PCB will be your testing set up. It is very important to think its design properly and according to the design specifications of the chip.
Note that results from this testing may force you to change your set-up. This means you will have to change your PCB to adapt to the results you got to be able to continue testing and get the feedback you consider important. No matter if results are good or bad, what you are looking for is data that allows you to take an educated decision: ‘Can this be a good solution and what do I need to change?‘
Sensor tag level
If you are in this phase, you will be more interested in testing the performance of the IC when embedded in a specific circuitry.
Again, the chip will be tested in a PCB or a similar substrate – it will depend on your design. You will be working with information from a datasheet but we can all misunderstand part of it at some point. However, you don’t just evaluate the chip against its specifications but you monitor its performance on your device, which may include sensors, power management circuitry, microcontrollers, data loggers, etc.
This is your testing set-up. It needs to be thoroughly designed and will require changes as you get results from it.
RFID solution level
It is not any different when you are evaluating RFID technology as a solution.
You can’t focus on a single tag model, a specific reader or antenna. Not even in a solution that already worked for a different end user.
Your application environment is specific to you and you need to think about a set-up to get results from. Not getting the results you want does not mean RFID technology is not a good fit for your application. It is the information on those results that you need to understand.
A simple change in your setup may give you the results you want. A well-known case are ‘on-metal’ tags for example, where a standard tag won’t work because it is attached to a metal but ‘on-metal’ tags will do the job perfectly.
You could even work your testing with standard tags attached to metal and use a spacer during your tests. This will help you assume performances of the solution in a variety of scenarios. It is your duty as the responsible of the implementation to know what assumptions to make in order to make the initial testing more cost effective while keeping the uncertainty low.
The key takeaway for RFID technology continues to be ‘Test!’ We want to give it an extra note here though: setup is paramount and needs to be well thought. The key for getting it right is knowing what information you need to look for.