Re: how far are RFID tags scanning distance?

On Wed, 23 Nov 2005 15:49:43 GMT, Mike Harrison <mike@xxxxxxxxxxxxxxx>
wrote:

>On Wed, 23 Nov 2005 08:07:23 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon@xxxxxxxxxxxxxxx>
>wrote:
>
>>On Wed, 23 Nov 2005 15:58:19 +0100, Sander <Big_Scary_Man@xxxxxxxxxxx>
>>wrote:
>>
>>>Nick wrote:
>>>
>>>>
>>>> The scanning distance we need would be around 3 meters. Do you guys
>>>> have any suggestion about the tags, and tag readers?
>>>
>>>Depending on circumstances 3 meters might be feasible with passive UHF
>>>tags. A lot depends on your exact application and requirements though.
>
>You'd need a BIG antenna on the tag, and/or a LOT of transmit power though.. possibly enough to
>raise health concerns if users were exposed continuously to it.

For range, the TAG's of choice are battery-powered, but utilize
sleep-mostly, wake-up-occasionally technologies to maximum battery
life.

Transmit TO the TAG is usually a low frequency (say 132KHz) to
optimize the receiver in the TAG.

Transmit FROM the TAG is usually UHF or up.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

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Relevant Pages

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