As the energy travels through the cable from the RFID reader to the RFID antenna (and back), power is lost and there is no way of getting around this fact. However, in order to ensure that each RFID antenna cable helps you achieve the level of performance you desire for your application, you can take steps to minimize the amount of loss that occurs.
The type of RFID antenna cable you need depends on a few key factors:
- the length of cable required (from the reader to the antenna),
- the read range desired (from the antenna to the RFID tag), and
- the gain of the antenna being used.
The longer the cable, the greater the loss. You can combat that loss by using a better-insulated, higher rated cable (see cable loss chart below). The downside to using a higher rated cable is that it is thicker and, as such, a little harder to work with as it doesn’t bend as easily as its lower rated cousins.
If the desired read range is relatively short (only a few inches to a few feet), you may still be able to use a lower rated cable, but if you want to maximize read range, then you’ll want to use a higher rated cable.
Lastly, when choosing a cable, you need to consider the gain of the antenna you are using. All things being equal (i.e. reader power setting, cable length and rating, RFID tag being used), if you were to use a lower gain antenna (e.g. 5 dBic) vs. a higher gain antenna (e.g. 9 dBic) you’d see a big difference in read range. So, factoring in the gain of the antenna is important as it can impact the type of cable you need in order to achieve your desired results.
Below we have included a Cable Loss Table showing you the loss per cable depending on length and LMR rating. Please add your thoughts on reducing cable loss in the comments section below.