Case Study: Portable Spectrum Analyser for Radio "bug" detection
A spectrum analyser solution developed to satisfy the increasing market demand, for a reliable system that has the capability to detect threat signals (bugging devices) in today's crowded spectrum.
In essence it was a custom made, integrated, touch screen Panel PC, with software programmable radio receivers. This portable Panel PC was designed to function as a radio frequency spectrum analyser, for detecting and identifying unwanted RF signals, displaying the results on the integrated touch screen.
An industry leader in the RF surveillance arena with a number of innovative specialist devices.
A reliable brief case style system, which had the capability to scan the RF spectrum for bugging devices under software control. It also included an audio channel to help to identify legitimate frequency usage such as TV and radio.
This customer currently had a product, which pin pointed and looked for different radio sources within a given space. It was a desktop, surveillance receiver with in-built RF detection, PC and display system. The product concept had been proved to be successful and was currently in production. However, its design required streamlining to improve the production and serviceability of the mechanics and address issues such as weight, processing power and cost.
There was a requirement to improve the performance, reduce the weight and lower the cost, while maintaining the very tight EMF emissions standards. For the application this latter point is critical. When detecting even modest levels of target signals it is imperative that the device itself is electrically quiet and well screened.
- To upgrade the current product, while enhancing its performance (CPU).
- To ensure the end user experience was enhanced with a better display and touch screen.
- To be quieter, or electrically tighter than the previous design.
- To fit within the original casing the customer had - custom built design.
- To have ultra low electrical noise emissions
- To be reliably reproducible in manufacture so that RF performance was maintained
- To use industrial long life components so that on-going re-qualification testing was minimised
- The weight had to be kept to a minimum for ease of use in the portable environment.
Selecting a critical gauge of aluminum sheet, as an RF shield and coarse material gave a balance for RF shield efficacy and reduced weight. Shape and form of the component parts gave strength to the design. After testing a range of metals, aluminum was used as it had lots of positive properties. This light weight metal would reduce emissions and was easily formed during the design process. Holes were inserted through the aluminum, which reduced the weight of the product even further and all its edges were rounded to present a good cosmetic finish, while stopping any radio frequencies (RF) from leaking out.
- The Panel PC's touch screen and display had a shielding mesh. This stopped emissions but allowed the screens to be seen with minimal obscuring and facilitated the function of the tactile touch screen.
- A 3.5 inch embedded motherboard was chosen, for its high performance, low power consumption and small footprint.
- The customers’ branding elements were maintained throughout the WES7 configuration.
- A customised desktop was also created within the Panel PC.
- The prototype scored highly and met all the customer’s requirements and goals.
- The customer was happy to receive a winning product, within its market place.
- Over 150 units were manufactured and shipped during the first 18 months of production