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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?

  • Hello Mark,

     

    When you are first looking at developing a radio for consumer use the first thing you need to do is contact the agency that regulates the spectrum in the area you wish to sell you product.  In your case this would be the National IT and Telecom Agency.  There website is http://en.itst.dk/.

     

    You need to describe to them what type of product you will be selling.  They will point you to the right regulations that you need to read in order to get approval to sell you product in Denmark.

     

    Once you know what the regulations are then you can contact the semiconductor manufactures to find out what solutions they have that you can use to develop your product.

     

    If you need help with this I would suggest you check out my website to get further information on how to get your project started and how to access technical assistance in development.

     

    http://www.pinterec.ca/services/wireless-development

     

    Hope this helps,

     

    Chris Pinter

  • 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