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The roadside reader. Is there a way to turn this image 90 degrees?
The pictures show a vehicle
RFID system installed for
toll collection in Norway. Can anyone identify the internal components of the active tag carried by every vehicle?
There's a bot that can be told to rotate photos but I don't know which one. Or it could be edited on your computer and a new version uploaded. †Dismas†|
(talk)17:21, 13 September 2016 (UTC)reply
Since it's possible to read the part number on 7 (1PT1039), we can tell it's a piezoelectric transducer (spec sheet here
[1]), apparently for generating sounds. The printing on the other chips is too small to read in this photo.
CodeTalker (
talk)
23:57, 13 September 2016 (UTC)reply
Wikipedia has an article about the
AutoPASS system in which this RFID or
DSRC transponder is used. There is no mention of an ability to make a beep noise that could surprise a driver. I speculate that it could be there for production testing i.e. when each unit is programmed with the vehicle identity, and/or is a means to alert someone to unpaid tolls or stolen vehicle.
AllBestFaith (
talk)
11:32, 14 September 2016 (UTC)reply
Component 2 is presumably a piece of
power electronics - maybe a
Crystal oscillator for
converting the DC current produced by the battery into pulses for electronics/driving an antenna. But as CodeTalker says, we need to know what's printed on the chips to know what they really are. All packages look basically the same. I think the precise antenna type is an aperture-coupled patch antenna - the microstrip lines on the front feed power to/from the slots visible on the back, and these in turn couple to the metal disc. So (in transmit mode) the signal flows up the printed
microstrip lines, then into the slots, then into the disc, which radiates them (I can't find an illustrations of this exact antenna, but
this one is quite similar,
as is this one). I think from the arrangement of the slots and the way that one arm of the microstrip is longer than the other means that this tag is
circularly polarized (which is good because it ensures that the orientation of the RFID tag doesn't matter too much), and the weird ring looks like a
Wilkinson power divider, which splits equally power between the slots while ensuring that power from one slot can't flow to the other.
Smurrayinchester08:13, 14 September 2016 (UTC)reply
At operating frequency 5.8 GHz a quarter wavelength is 1.3 cm in air. Here are the markings on the microchips:
Welcome to the Wikipedia Miscellaneous Reference Desk Archives
The page you are currently viewing is a
transcluded archive page. While you can leave answers for any questions shown below, please ask new questions on one of the
current reference desk pages.
The roadside reader. Is there a way to turn this image 90 degrees?
The pictures show a vehicle
RFID system installed for
toll collection in Norway. Can anyone identify the internal components of the active tag carried by every vehicle?
There's a bot that can be told to rotate photos but I don't know which one. Or it could be edited on your computer and a new version uploaded. †Dismas†|
(talk)17:21, 13 September 2016 (UTC)reply
Since it's possible to read the part number on 7 (1PT1039), we can tell it's a piezoelectric transducer (spec sheet here
[1]), apparently for generating sounds. The printing on the other chips is too small to read in this photo.
CodeTalker (
talk)
23:57, 13 September 2016 (UTC)reply
Wikipedia has an article about the
AutoPASS system in which this RFID or
DSRC transponder is used. There is no mention of an ability to make a beep noise that could surprise a driver. I speculate that it could be there for production testing i.e. when each unit is programmed with the vehicle identity, and/or is a means to alert someone to unpaid tolls or stolen vehicle.
AllBestFaith (
talk)
11:32, 14 September 2016 (UTC)reply
Component 2 is presumably a piece of
power electronics - maybe a
Crystal oscillator for
converting the DC current produced by the battery into pulses for electronics/driving an antenna. But as CodeTalker says, we need to know what's printed on the chips to know what they really are. All packages look basically the same. I think the precise antenna type is an aperture-coupled patch antenna - the microstrip lines on the front feed power to/from the slots visible on the back, and these in turn couple to the metal disc. So (in transmit mode) the signal flows up the printed
microstrip lines, then into the slots, then into the disc, which radiates them (I can't find an illustrations of this exact antenna, but
this one is quite similar,
as is this one). I think from the arrangement of the slots and the way that one arm of the microstrip is longer than the other means that this tag is
circularly polarized (which is good because it ensures that the orientation of the RFID tag doesn't matter too much), and the weird ring looks like a
Wilkinson power divider, which splits equally power between the slots while ensuring that power from one slot can't flow to the other.
Smurrayinchester08:13, 14 September 2016 (UTC)reply
At operating frequency 5.8 GHz a quarter wavelength is 1.3 cm in air. Here are the markings on the microchips: