Antenna Modelling – A Tale of Two Small Antennas

Two recent assignments in regard of ISM band antennas needed very different solutions, despite there being an important common aspect of being confined within a small mechanical envelope. They illustrate the need for a flexible and pragmatic approach when working on the incorporation of antennas in small products.

For one assignment, the client already had a promising partial solution for operation within the mechanical constraints of their product, but with which we were able to see a problem owing to the lack of an adequate counterpoise. We proposed a simple resolution to improve performance by modifying the way the partial solution was used. Then by developing an electromagnetic model for the arrangement, appropriate tuning and matching components and values were determined for this new configuration at each of the operating frequencies of interest.

For the other assignment, the constraints and freedoms were different, including the lack of any suitably sized cavity, but there was an additional fact concering the operational specification that turned out to be useful.

After considering options for where an antenna may be incorporated, options were modelled and refined, yielding an efficient, balanced 2D form for an outer surface that was tolerant of other (particularly metal) structural elements in its immediate neighbourhood.

By virtue of its efficiency, this structure presented the best impedance match for the RF circuit, but the match was still relatively poor, and a matching network to produce what would normally be considered a good match would only work for a narrow frequency band. Further, the actual centre frequency of this band would be prone to variation, due to various component and dimensional tolerances and temperature variations.

However, given the fact that the required range for transmission and reception was quite short, the relatively poor match, with only moderate further adjustment, would still permit adequate power to be radiated, even when using the intended RF circuit within the intended overall power budget. Also, crucially, this would be obtained with a sufficiently broad frequency-response peak for the antenna, to give robust antenna performance with stability and repeatability in output despite the aforementioned sources of variability. Hence, what otherwise may have been a problem, was in fact a solution that was good enough in the particular application.

Induction Heater Developments

With a successful 1200W induction heater as an established commercial product in the automotive sector, we are being consulted regarding design and development of higher-power and lower-power designs for varying mechanical formats and application areas, with advanced operational, control, protection/safety and application features.

To learn more on how we may assist with induction-heater design, please see our page on Induction Heaters.

Metal Detector – Product Launch

An industrial pulse-mode metal detector developed by WRL Consultancy, in conjuction with mechanical design support from the client’s team, has now been launched by the client at a recent trade-show. Pulse-mode detection is particularly useful for distinguishing the metal signal, via time-domain means, when the return signal from the materials being inspected is generally variable and unpredictable and hence difficult to calibrate for with continuous-wave detection.

The launch followed prototype stages, starting with proof-of-concept, during which adaptations and refinements were made and tested to suit the clients specific requirements and the particular characteristics of the intended field of application.

Ongoing close technical support of the detector will assist the scaling up of production, further enhance its capability, and also yield product range variants, bespoke designs and an enhanced feature-set for end customers.

Please see our page: Metal Detection, Sensing and Electromagnetic Discrimination

Bespoke and Unconventional RFID

Announcing a new website page that follows the development of our services and increasing activity for us in this area.

Applications for custom and unconventional RFID exist where a particular problem or set of problems prevents a more standard approach, or where a custom approach is simply more efficient or effective.

Particular solutions generally depend on the design constraints and opportunities relating to the details of the respective problems. Developing the appropriate concept is a key part of the work, and may produce patentable ideas.

For further information please visit the page Bespoke and Unconventional RFID

Phone Number Change

Following a technical upgrade to our phone system, we advise an amendment to our contact details with a new main phone number 0344 500 2111. Our earlier numbers will continue to work for the foreseeable future, for the convenience of those who already have them. The calling cost for an 03.. number is the same as for a standard geographic number (i.e. 01.. & 02..).

Radio Survey – Coverage

We recently completed, for an extensive industrial site, a radio communications outdoor coverage survey and report with interpretation of the findings. The survey was required so that difficulties with communications over the site could be better understood and regions of problematic signal propagation identified. Prior to the survey, we provided guidance with regard to clarifying the client’s survey plan to reconcile practical requirements and economic considerations. This is one of a portfolio of services that we can provide – please see our Services section.