Wireless magic

Citation

Loughlin, C. (2003), "Wireless magic", Sensor Review, Vol. 23 No. 2. https://doi.org/10.1108/sr.2003.08723baa.001

Wireless magic

Wireless magic

I think it was Arthur C. Clarke who said, "Any sufficiently advanced technology is indistinguishable from magic".

I do not believe in magic, but I do believe that there is a lot that we have yet to discover and to achieve – which, according to Clarke, probably amounts to the same thing.

Our themes for this issue include Radio Communications, and while this would have been considered as magic prior to 1895 when Guglielmo Marconi first achieved long range (over a mile) wireless communications; these days we take it pretty much for granted.

Taking things for granted is a very dangerous state of affairs and anyone considering venture into the world of wireless communication of sensor data would do well to be rather more circumspect. I am by no means an expert on radio communication however I have spent quite a lot of time working with the development of radio based systems and do at least know that there is a lot that I do not know and have yet to learn.

These days the headlines are full of "Bluetooth", "802.11b" and "2.4GHz" and they all relate to digital systems. However radio is anything but digital and this creates a whole series of potential problems that lie in wait to confront the unwary.

My own background is far more digital than analogue and I am quite happy in the on/off world of bits and bytes and serial data communication. I am less confident when confronted with systems that require meticulous attention to ground planes, power supply isolation and PCB track layouts, where how you turn a corner and whether or not you use a thru-hole can have a major impact on system performance.

Even if your circuit design and PCB layout is perfect, you still need to get the RF signal into your antenna and get it radiated without too much attenuation or frequency shifting. This apparently simple function is heavily influenced by connecting wires, presence of adjacent materials, the type of plastic from which the enclosure is made and whether or not the antenna has a good ground plane from which to launch the RF into the ether. Even when all of the above has been optimised, your long suffering system is then placed at the mercy of the surrounding environment.

If you still want to use radio after reading the above then please do continue. I am a big fan of radio and the benefits it can provide. But do make sure you know what you are doing before you start. Our tutorial "Implementing Wireless Communications" should be a big help and I would add the following suggestions.

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  If you can buy it then do so. Wheels are expensive to invent.

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  Surf the web for application guidelines. Most radio communications text books are incomprehensible to all but initiated.

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  Prototypes must be physically the same as the target solution, not just electrically identical.

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  Do not believe anyone who says it is easy.

There can be no doubt that we are headed for an increasingly wireless future and that future will see radio communications as an intrinsic part of the majority of sensor systems.

Sounds like magic to me.

Clive Loughlin

Call for paper

SR 23:4 Biosensors + BiometricsCopy in deadline: 16 May 2003; Publication: 26 September 2003;Personal identification and security applications. Biosensors and chemical analysis.