Bespoke and Unconventional RFID

Bespoke, customised and unconventional RFID has become a significant area of activity for WRL Consultancy.

Applications may include: those served generally by RFID but where there are particular difficulties or constraints, also verification of the ontinued presence of particular items, location of various types of objects in variety of settings and contexts, and situations where
conventional protocols and widespread compatibility are not necessary, whereas custom protocols and operating principles would be much more efficient and effective.

Just one example of the type of scenario would be a short range application, yet with the need for a small tag antenna to situated where there is high attenuation of the reader field, and with low emissions limits at usual frequencies forcing a choice of operating frequency where higher levels are possible, or even the use of very different frequencies for each direction. Limited antenna size, a challenging distance and toleration of a difficult terrain for the passage of the signal are factors that often arise.

The solution generally depends on the details of the problem, the constraints and key requirements it imposes – and the degrees of freedom and opportunities that may still exist among these, such as: distance; practical antenna sizes and locations; emissions limits (which in certain applications are different from usual limits for licence-free short-range devices); usage, general practicalities and ergonomics; safety; terrain between reader and tag (its tendency to absorb, scatter or obstruct); environmental; EMI; available power sources – a connection, or batteries (what voltage, size, lifetime, power delivery, technology, cost), or derived from RF field or AC magnetic field; and hence whether the tag/transponder is active, semi-active, or passive.

The concept development and early design process can include: close consultation with the client to understand the state of knowledge of all relevant parameters; research; link calculations; electromagnetic modelling and analysis; prediction of side-band emissions, and investigation of their possible mitigation; selection of suitable operating frequencies – considering permitted frequencies, levels, bandwidths and sidebands; custom operating modes / principles; special antenna design and circuit concepts; looking at existing IP and assisting with the materials and technical support for patent applications with regard to possibly novel ideas that do emerge which enable and/or differentiate the product.

We are pleased to discuss ideas, provide advice and perform feasibility work, site visits, concept development and full development with ongoing support, test development and emissions/EMC compliance.