24 April 2012
Our research concerns antenna design and propagation of radio, both for wireless communication devices as well as radar. While we are actively involved in antenna design and modelling of propagation channels for some of the many applications of wireless systems, the work in our letter focuses on analysis of simulated radar impulses based on the ultra-wideband (UWB) standard. While much research has been carried out with regards to UWB communication systems, there are relatively more applications to be devised using radar, and this is one such case.
In the future, everything will become networked – there will literally be an ‘internet of things’. For the domestic user, every electrical item including the cooker, kettle, toaster and fridge will be able to connect and then send information to one’s mobile terminal. The fridge could assist the busy individual in their shopping by automatically indicating what quantity of essentials such as milk, eggs or orange juice are in stock in their fridge. It would be possible for an intelligent fridge to know if there is a bottle of milk/orange or a box of eggs present in a fridge by use of a radio frequency identification (RFID) tag, but this would not indicate how much milk was left in the bottle or how many eggs were left in the box. At best it would only indicate the use by date. This is where UWB comes in to assist RFID, in that it has the capability to ascertain the quantity of milk or eggs using low-cost radar techniques.
The advantage of this method is that it is based on extracting complex natural resonant (CNR) frequencies combined with analysing the polarisation of the radar impulses received in response from the eggs that the system is detecting inside a fridge. Therefore the method is not a full imaging mechanism, but rather a low-cost method for the purposes of identifying the presence of eggs in a box and ascertaining their number, which is the actual information necessary in the context of our ‘internet of things’.
Certainly this would be possible to apply to other applications that use radar, such as security and military for the purposes of using a low-cost and efficient technique to find the quantity of a known item such as the a volume of a liquid in a small bag. However, the main limitation will be that the low power of UWB will restrict its range.
Another area we are actively working on is near field communication (NFC) devices with regards to the internet of things. There are an increasing number of mobile handsets, including NFC, which is a low cost and simple radio, designed to exchange small quantities of data between two devices over a short range. One major application of NFC is contactless payments, but there are a number of ways in which NFC can be used intelligently. For example, as NFC is compatible with RFID tags at the same frequency, it could not only sense the presence of a tag in close proximity, but also find its position.
Building of low-cost devices that can support ‘things’ that need only communicate limited quantities of information will be a big challenge. Furthermore, it will be important to ensure they sustain compatibility with current and future standards in wireless.
The Letter presenting the results on which this interview is based can be found on the IET Digital Library.
Browse or search all papers in the latest or past issues of Electronics Letters on the IET Digital Library.