RFID Antenna Selection guide


Times-7 has developed an antenna selection guide, which helps to break down which type of beam shape is right for your application and then which of our Times-7 RAIN (UHF) RFID antenna is the right fit for you.

WHY IS THE BEAM SHAPE IMPORTANT?

System integrators are often challenged with 100% tag detection accuracy and stray (unintended) tags isolation. Although the tag readability and stray tag filtering can be achieved using the features in the reader software, reader antennas and their specific beam shapes do play a vital role in these aspects. 
An uncontrolled RF spill by far-field antennas causes stray tag detection while low power RF radiation leads to low tag detection read accuracy. 
Based on these facts, Times-7 created an antenna guide approaching the selection process from a new angle.  

RFID ANTENNA BEAM SHAPES

Times-7 antennas can be broadly categorized based on their beam shape viz., spherical beam, fan beam. Spherical beams will have symmetric radiation whereas fan beams will have asymmetric radiation in the antennas’ azimuth and elevation planes. The antenna’s gain and directivity are a function of the beam shape. A narrower spherical/fan beam antenna will have higher gain compared to a wider beam antenna.

RFID beam shape

Antennas with the high gain spherical beam are recommended to those applications that require a spotlight type read zone whereas a high gain fan beam is suggested for asymmetric read zone creation. The former will be useful for applications like vehicle tolling in different toll booth’s lanes while the latter can be used in creating an RFID portal that has a very narrow RF spill to eliminate the stray tag reads but has a wide RF energy coverage within the portal. Since near-field antennas do not have a far-field radiation pattern, their read zone characterization is different compared to the far-field antennas.  

 

 

The RAIN RFID Reader Antenna Selection Guide was first published as a poster at the 2019 IEEE International Conference on RFID during the RFID Journal Live! 2019 in Phoenix. The original poster can be viewed here.