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Choosing a frequency band

Former Member

Hi there!

 

I'm designing a wireless consumer electronics product that needs very little range... (max 3 meters) and also very little power usage..

 

one part of the device needs only TX capabilities, and the other only RX capabilities.

 

My problem is that i don't know how or where to find information on which frequency bands are available/legal to use for consumer electronics.

 

I am from Denmark and this is also primarily where the product will be sold, so I KNOW there are rules and regulations regarding the use of frequency bands..

 

Is there a wireless guru here that can point me in the right direction?

Parents

  • Firstly, the fact that you only need 3 meters means that you don't have a tough design problem.  You can probably use a SAW based transmitter and a 50 ohm resistor as your antenna.

     

    In the EU, the 433 MHz and 868MHz bands are general assigned for "unlicensed use".  I am assuming your product is a simple consumer product and would operate in these bands.

     

    Of the two, I would pick the 433 MHz band.  For long range apps, it is tough in the EU because it is so overused.  However, for a very short range app like yours, it is perfect because the rules for that band are much simpler.

     

    There is a plan to kill 433 MHz, however, but it has had a lot of opposition.  To my knowledge, that plan was introduced in the late 90's, but it still hasn't been implemented.

     

    The 868MHz band is sliced into many sub-bands, each of which is restricted by bandwidth (ie. data rate), ratio of on/off time, total power output, and application.  You can find a copy of this band plan here:

     

    http://www.cdt21.com/products/compliance/868mhz.asp

     

    If you have any other questions, let me know.  I have a lot of experience with this stuff.  I was the Director of Engineering in the mid 90's  of Linx Technologies and founded Radiotronix in 2000.

     

    Best Regards,

     

    Steve The RF Guy

    God Bless

Reply

  • Firstly, the fact that you only need 3 meters means that you don't have a tough design problem.  You can probably use a SAW based transmitter and a 50 ohm resistor as your antenna.

     

    In the EU, the 433 MHz and 868MHz bands are general assigned for "unlicensed use".  I am assuming your product is a simple consumer product and would operate in these bands.

     

    Of the two, I would pick the 433 MHz band.  For long range apps, it is tough in the EU because it is so overused.  However, for a very short range app like yours, it is perfect because the rules for that band are much simpler.

     

    There is a plan to kill 433 MHz, however, but it has had a lot of opposition.  To my knowledge, that plan was introduced in the late 90's, but it still hasn't been implemented.

     

    The 868MHz band is sliced into many sub-bands, each of which is restricted by bandwidth (ie. data rate), ratio of on/off time, total power output, and application.  You can find a copy of this band plan here:

     

    http://www.cdt21.com/products/compliance/868mhz.asp

     

    If you have any other questions, let me know.  I have a lot of experience with this stuff.  I was the Director of Engineering in the mid 90's  of Linx Technologies and founded Radiotronix in 2000.

     

    Best Regards,

     

    Steve The RF Guy

    God Bless

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