modifying a commercial mobile phone jammer to jam RFID
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modifying a commercial mobile phone jammer to jam RFID

by betomo on Thu Nov 20, 2008 12:41 pm

is it possible to modify a commercially available mobile phone jammer to jam RFID tags?
as I understand a phone jammer works by sending static signals that overpower the mobile phones in the vicinity, thus rendering them unusable. Mobile phones work in the range of 850 to 2200 Mhz
Could the frequency of the jammers be modified as to work in the range of 30-300khz, 3-30mhz, 300mhz-3Ghz and 2-30 Ghz?
Would this disable the operation of any RFID tags in the vicinity?
How could you do that?
betomo
 
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Re: modifying a commercial mobile phone jammer to jam RFID

by aqisnotliquid on Thu Nov 20, 2008 4:04 pm

If a commercially available RF jammer has a built-in PLL system, with a bit of hardware/software hacking you -should- be able to reset the frequency range (provided that the actual VCO in the device supports that range). However, if the device is built to block cell phones and only cell phones, I think the only option you have is to replace the VCO with one of the right frequency.

Here's a table of different VCO's offered by MiniCircuits with their frequency range:
Image

Also, the generic frequencies for RFID are:
125 - 134 kHz
13.56 MHz
UHF (400 – 930 MHz)
2.45 GHz
5.8 GHz

So your best bet (if you want to block all RFID) is to either build a Wave Bubble or find another RF jammer that includes a PLL that you can use to set the range of the VCOs.
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Re: modifying a commercial mobile phone jammer to jam RFID

by Blair-B on Mon Sep 13, 2010 2:26 am

betomo wrote:is it possible to modify a commercially available mobile phone jammer to jam RFID tags?
as I understand a phone jammer works by sending static signals that overpower the mobile phones in the vicinity, thus rendering them unusable. Mobile phones work in the range of 850 to 2200 Mhz
Could the frequency of the jammers be modified as to work in the range of 30-300khz, 3-30mhz, 300mhz-3Ghz and 2-30 Ghz?
Would this disable the operation of any RFID tags in the vicinity?
How could you do that?

Just purchase a commercially available cell phone jammer,it can block almost all kinds of wireless signals.
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Re: modifying a commercial mobile phone jammer to jam RFID

by ramon on Mon Apr 11, 2011 4:42 am

aqisnotliquid wrote:If a commercially available RF jammer has a built-in PLL system, with a bit of hardware/software hacking you -should- be able to reset the frequency range (provided that the actual VCO in the device supports that range). However, if the device is built to block cell phones and only cell phones, I think the only option you have is to replace the VCO with one of the right frequency.

Here's a table of different VCO's offered by MiniCircuits with their frequency range:
Image

Also, the generic frequencies for RFID are:
125 - 134 kHz
13.56 MHz
UHF (400 – 930 MHz)
2.45 GHz
5.8 GHz

So your best bet (if you want to block all RFID) is to either build a Wave Bubble or find another RF jammer that includes a PLL that you can use to set the range of the VCOs.

where i can buy a operable bubble wave
ramon
 
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Re: modifying a commercial mobile phone jammer to jam RFID

by TheFallen on Thu Apr 28, 2011 7:47 pm

I'd say that unless you knew how to build a wavebubble modifying a commercial cell phone jammer would be a little bit beyond you.

As for jamming RFID signals, I see only 2 uses. Theft, or paranoia. Theft, try a magic bag, but really, don't steal. Paranoia, heh, now they know </dark joke>.

if you build a wavebubble with a ROS-1300+ then you can go down to 300MHz on the low range, which covers the UHF tags. the 2.45GHz tags are covered by most high band VCOs that have been tried on a wavebubble. The 5.8GHz capable VCOs have never really been tried on wavebubbles, because the PLL chip (the LMX2433) only goes up to 3.6GHz. It's my understanding the high level tags, 200MHz up, are typically active tags so have a battery and would be found in LARGE scale shipping endeavors.
125-134kHz/13.56MHz tags on the other hand are found in shopping tags, contactless ID cards/payment cards/travel cards. I guess what I'm trying to say is that a wavebubble would be pretty useless for the locations you'd encounter these either low frequency or high frequency tags.
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