News

RF-to-DC-Powered Batteryless Electronic UHF Retail Price Tags

April 10, 2018 by Paul Shepard

Powercast Corporation will demonstrate the industry's first Batteryless Electronic UHF (Ultrahigh Frequency) Retail Price Tag at RFID Journal LIVE! (Booth #1260) being held in Orlando, April 10 - 12. It is a finalist for the show's Best New RFID Product 2018 Award, with winners announced April 12.

The demonstration will feature Powercast's RF-to-DC power harvesting technology which can wirelessly update an electronic paper (ePaper) display, sending data and power over the air up to two meters away using a standard UHF RFID reader. Powercast's technology enables quick electronic price changes, operates perpetually without batteries, and works with typical UHF RFID readers (handheld and fixed).

Powercast developed the concept tag to free retailers from having to change paper labels as well as the batteries required by the industry's battery-powered electronic price tags - both of which are labor-intensive jobs. An RFID reader can update a whole shelf of product prices within a few seconds.

"We have been working with several companies on the tag," said Charles Greene, Ph.D., Chief Operating & Technical Officer, Powercast Corporation.

The industry's first Batteryless Electronic UHF Retail Price Tag, developed by Powercast, features RF-to-DC power harvesting technology which can wirelessly update an ePaper display, sending data and power over the air using a standard UHF RFID reader. It enables quick electronic price changes, operates perpetually without batteries, and can update a whole wall or shelf of product prices in a few seconds.

"The tag uses zero power when not in the field because it doesn't have a power source.  When in the field, we accumulate energy in a small capacitor (charge and fire) for a second or two.  The peak power is required by the display and depends on the size.  The peak power usage in the tag we have developed is 50mW for less than a second, with an average power of 4mW," Greene added.

How Powercast's Batteryless Electronic UHF Retail Price Tag Concept Works:

Select the tag(s) to update and the new price in an app on a handheld UHF reader. (Retailers can easily integrate this function into their system.) Point the reader at the price tag, up to two meters away, to securely send pricing data and RF energy over the air to Powercast's tiny PCC110 Powerharvester® wireless power receiver chip embedded in the tag.

The chip converts RF to DC to power the tag without batteries, and updates the display with the new, authenticated price in a few seconds. The tags don't need batteries because they can harvest enough power just from a UHF RFID reader to operate perpetually.

Other Enabling Technology in the Batteryless Price Tag:

Powercast chose an ePaper display from E Ink because it can efficiently maintain the price image on the tag even when it's outside of/not being directly powered by the UHF field. With both active matrix and segmented displays possible when designing electronic tags, the E Ink segmented display Powercast selected offers a more economical solution than the active matrix displays typically used in battery-powered electronic tags. Further, it doesn't require a high-end display driver.

An evaluation kit for the Batteryless Electronic UHF Retail Price Tag is expected in Q4 2018 from distributors Arrow Electronics and Mouser Electronics.  The concept tag is available for license or Powercast will work with partners to design their own batteryless price tags using Powercast's PCC110 chip.