RFID Antenna Patterning Test Playbook

by on in RFID, RFID Technology

Checklist for Effective RFID Antenna Testing

If your RFID effort involves the hands-on testing of your system and application, it may be necessary to set up a small RFID test lab. One of the first tests you may wish to perform is the RFID antenna patterning test. The results from this test will greatly aid you in designing and selecting the proper RFID antenna equipment, reader, and tags for your final deployment.

STEP 1: Setup the test RFID reader and antenna

Who: RFID Test Engineer

Actions:

  1. Set up a fixed RFID reader and set it to the factory defaults as a control.
  2. Attach a single transmit and receive RFID antenna to the reader.
  3. Mount the antenna to a test stand (e.g., PVC antenna stand, camera tripod). The top of the antenna should be about four feet off the ground.

STEP 2: Make some test tagged assets

Who: RFID Test Engineer

Actions:

  1. Make several test assets by attaching the RFID tags. A piece of cardboard will work just fine.
  2. Attach the test asset to the test stand or tripod at the same height of the antenna, i.e., four feet.

STEP 3: Start the reader

Who: RFID Test Engineer

Actions:

  1. Place the tagged asset directly one foot in front of the RFID antenna.
  2. Begin reading the RFID tag.
  3. Move the tag in six inch increments to each side of the antenna until the fixed RFID reader can no longer read the tag on either side.

STEP 4: Record the test findings

Who: RFID Test Engineer

Actions:

  1. Record the location of the last successful read to either side.
  2. Get the outward limit of the interrogation zone at one foot away and record it.

STEP 5: Perform next read test

Who: RFID Test Engineer

Actions:

  1. Place the tagged asset directly in front of the RFID antenna under test but place it two feet away this time.
  2. Again, move the tag laterally in six inch increments until the antenna can no longer successfully interrogate the tag.
  3. Record the location of all of the successful reads and note the position of the first unsuccessful read on each side of the antenna.

STEP 6: Perform final direct read tests

Who: RFID Test Engineer

Actions:

  1. Continue moving the asset back from the antenna one foot at a time until the antenna can no longer read the tag when it is placed directly facing the antenna.
  2. Perform the lateral tests on each side of the antenna as in steps three, four, and five.
  3. Record how far back and how far to each side the antenna can successfully read the tag.

STEP 7: Change RFID Reader power settings and repeat

Who: RFID Test Engineer

Actions:

  1. Change the power settings of the fixed RFID reader.
  2. Repeat steps three through six in the same way.
  3. Record the findings.
  4. Note the differences that the varying power levels on the reader have on creating the effective antenna interrogation pattern.
  5. Create a graphical representation of the antenna pattern. (This test can be repeated for any number of antennas). The more read point locations you find for read/no read the more accurate your antenna test pattern will be. The pattern should be fairly symmetrical. If it is not look for anomalies in your testing location (e.g., metal shelving, metal door frames).

The RFID Antenna pattern test gives you a basic understanding of what your read zone (aka RF bubble) is for this antenna/reader/tag system combination. The antenna pattern test helps you design a much more accurate and effective RFID system than you would have with just trial and error.

As a reminder, always be sure to document the test set-up and results. If there is follow-on testing performed by new people, it will allow the latest results to be compared with older findings. Documentation also helps new personnel to come up to speed more quickly in the RFID equipment and test techniques that are used.

In addition to the RFID antenna pattern test, there are several other basic tests that you can perform in your lab. These include:

  • RFID Reader performance tests for distance, speed, and accuracy
  • SKU tests
  • RFID tag and label characterization tests
  • Middleware and database comparison tests
  • Vendor-specific hardware and software tests

For more information on RFID including readers, antennas, printers, labels & tags, and accessories contact us at the Gateway RFID store (https://gatewayrfidstore.com/).