The Unlicensed Bands



Wire antenna

A very good antenna to use for maximum range.  Use a length of wire (or a PCB track) 1/4 wave length (e.g. 172mm for 433MHz).  The optimum is to use the wire straight, but it can also be bent into a 'L 'or 'U' shape if necessary (it will reduce the range a bit but it still works well).

A wire antenna is better than PCB loop

Helical (Coil) / Spring antenna

Also commonly used.

PCB loop

Good for ease / low cost of manufacture, but range is reduced.





We benefit hugely from resources on the web so we decided we should try and give back some of our knowledge and resources to the community by opening up many of our company’s internal notes and libraries through mini sites like this. We hope you find the site helpful.
Please feel free to comment if you can add help to this page or point out issues and solutions you have found, but please note that we do not provide support on this site. If you need help with a problem please use one of the many online forums.


  1. N.Lavakumar

    2 years ago

    Excellent work

    Thank you a lot

    I am a hobbyist in Chennai, Tamilnadu, India.


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