New Attitudes to UHF Revealed in Tokyo and Cambridge UK
IDTechEx
September 2007
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UHF RFID is of interest in the printing of electronics because the antennas are often printed with silver ink today, either by gravure, flexo or screen printing and the logic will be printed one day - all to save cost. It is one of the fastest growing types of RFID because it can sometimes give longer range, better multi-tag reading and so on but it is a long way from being the most popular RFID frequency by money spent and it is the only frequency at which the tag makers typically lose money. This is because they are pricing for high volumes which have yet to come.
At the IDTechEx conferences Printed Electronics in Asia 11-12 September and RFID Europe in Cambridge UK 18-19 September it was clear that attitudes to UHF RFID are changing. The East Asians were intrigued by the rush to UHF in the West and were keen to follow when their radio regulations permitted these frequencies at realistic power levels. That has now happened and UHF RFID is successfully used on such things as mail bags in China and airport baggage. There has been a honeymoon period when UHF was being tested for a very wide variety of applications in the East and was spoken of a solution for most challenges.
That period is now over, because some disappointments have restricted the vision to a narrower range of applications. The Japanese Government has been concerned that this frequency can interfere with heart pacemakers, so it now requires sites to display notices asking people with pacemakers to keep at least one meter from such tags. That has made one major store chain cancel a UHF trial. Another setback has been radio regulations sometimes permitting only narrow bandwidth, because this can cause a problem with readers interfering with each other and designers being unable to escape interference from other devices.
Major advance by Impinj
Impinj acknowledged the considerable problems with water and metal with conventional (ie “Far Field”) UHF in its presentation but it has now fully proved an alternative, notably for item level tagging, where so called Near Field UHF is used with inductive coupling mimicking the way an HF tag works. Range is modest at no more than 50 centimeters but that is no problem for most item level tagging. The antenna has a simple single turn of printed metal, this being cheaper than the HF alternative which would typically need seven turns and a crossover.
At the IDTechEx conferences Printed Electronics in Asia 11-12 September and RFID Europe in Cambridge UK 18-19 September it was clear that attitudes to UHF RFID are changing. The East Asians were intrigued by the rush to UHF in the West and were keen to follow when their radio regulations permitted these frequencies at realistic power levels. That has now happened and UHF RFID is successfully used on such things as mail bags in China and airport baggage. There has been a honeymoon period when UHF was being tested for a very wide variety of applications in the East and was spoken of a solution for most challenges.
That period is now over, because some disappointments have restricted the vision to a narrower range of applications. The Japanese Government has been concerned that this frequency can interfere with heart pacemakers, so it now requires sites to display notices asking people with pacemakers to keep at least one meter from such tags. That has made one major store chain cancel a UHF trial. Another setback has been radio regulations sometimes permitting only narrow bandwidth, because this can cause a problem with readers interfering with each other and designers being unable to escape interference from other devices.
Major advance by Impinj
Impinj acknowledged the considerable problems with water and metal with conventional (ie “Far Field”) UHF in its presentation but it has now fully proved an alternative, notably for item level tagging, where so called Near Field UHF is used with inductive coupling mimicking the way an HF tag works. Range is modest at no more than 50 centimeters but that is no problem for most item level tagging. The antenna has a simple single turn of printed metal, this being cheaper than the HF alternative which would typically need seven turns and a crossover.
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