Hello All,
I'm looking for some info on a 900MHz antenna that I found on a device.
It is a RFID reader, working in the 912-928 UHF band. You can
see a picture of the device here:
http://www.morerfid.com/details.php?subdetail=Report&action=details&report_id=4845&display=RFID
This plugs into a USB port and read RFID tags at the other end.
It has a range of 3 feet / 1 meter, along the end direction, so the
antenna is highly directional. I'm curious to find out what type of
antenna this is.
I took apart the thing, and found that there is an alumunum extrusion
in the middle, AROUND the PCB. (It is the darker middle portion in the above picture) It is a tube with an elliptical cross section.
I made a rudimentary drawing of the innards below:
http://img.photobucket.com/albums/v335/cultclassic999/Untitled-1.jpg
In my drawing the light blue thing is the tube. I'm assuming this is the antenna. There is some kinda rubber-like connector between the PCB and the aluminum tube, at the middle of the tube. Could this be a feed line?
The edges of the PCB shows some copper areas near the tube (yellow in my sketch), which could be connected to the tube, I'm not sure.
The whole antenna is about 2 inches long and about 3 inches in circumference. So I'm amazed how this could work in the 900MHz range so well.... Isn't the wavelength like 33 cm or something? It's also HIGHLY directional, which is something I'm looking for...
Anybody know what type of antenna this could be? I'm a mechanical engineer, so any info that could point me in the right direction would be greatly appreciated!!!
TIA
I'm looking for some info on a 900MHz antenna that I found on a device.
It is a RFID reader, working in the 912-928 UHF band. You can
see a picture of the device here:
http://www.morerfid.com/details.php?subdetail=Report&action=details&report_id=4845&display=RFID
This plugs into a USB port and read RFID tags at the other end.
It has a range of 3 feet / 1 meter, along the end direction, so the
antenna is highly directional. I'm curious to find out what type of
antenna this is.
I took apart the thing, and found that there is an alumunum extrusion
in the middle, AROUND the PCB. (It is the darker middle portion in the above picture) It is a tube with an elliptical cross section.
I made a rudimentary drawing of the innards below:
http://img.photobucket.com/albums/v335/cultclassic999/Untitled-1.jpg
In my drawing the light blue thing is the tube. I'm assuming this is the antenna. There is some kinda rubber-like connector between the PCB and the aluminum tube, at the middle of the tube. Could this be a feed line?
The edges of the PCB shows some copper areas near the tube (yellow in my sketch), which could be connected to the tube, I'm not sure.
The whole antenna is about 2 inches long and about 3 inches in circumference. So I'm amazed how this could work in the 900MHz range so well.... Isn't the wavelength like 33 cm or something? It's also HIGHLY directional, which is something I'm looking for...
Anybody know what type of antenna this could be? I'm a mechanical engineer, so any info that could point me in the right direction would be greatly appreciated!!!
TIA
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