Company profi le: Stealth Case Glass powers wireless technology

Glass powers wireless technology

� In a residential setting, one antenna window per room is typically recommended to achieve the best results.

Stealth Case won the Innovation of the Year category at the recent British Glass Focus awards. Mika Partanen* describes the award-winning technology, which is installed in glass and improves indoor wireless connectivity.

Congratulations on your innovation of the year award at the recent British Glass Focus awards.

1 Can you tell us more about the device? Thanks! Our new generation glass antenna dramatically improves indoor wireless connectivity – in other words, it enables faster download and upload speeds and better call quality for the people inside buildings. It can be added to window glass at fabrication stage and does not require power, maintenance or special installation to function. Importantly, it is virtually undetectable to human eye and does not compromise window’s thermal performance.

2 What gave you the idea for this technological innovation? A few years ago, our founder & CTO Juha moved to a newly completed apartment building in Tampere, Finland only to realise he could barely get a connection on his mobile phone. He realised this was caused by the attenuation of the building materials. Building on his experience in antenna design, Juha came to view windows as a natural entry place for mobile signals (along with light) into buildings. In hindsight, we think he was right!

� Mika Partanen, Lead - StealthCase International Business Development. 3 Where does it work? What type of location is it more suited for? Our glass antenna works by reversing the attenuation of building materials – window glass in this instance. It brings the mobile network signal strength you would find outside the building, into the building. That means the antenna works wherever there is mobile coverage outdoors. It benefits especially low-E windows since they tend to attenuate wireless signals heavily. As for building types, especially the ones with concrete, brick, stone or metal exteriors stand to benefit from windows with glass antennas.

4 How does it work (specifically in glass)? Our technology uses a laser to print a twodimensional pattern on window glass at the fabrication stage. The laser removes extremely thin traces of the metal coating on the glass to create a

passive antenna pattern in the desired area (e.g., close to the window edge; there is no need to cover a substantial area). Using beam forming technology commonly found in radars, this antenna pattern then “grabs” the signals arriving from the serving base station(s) outside and spreads them indoors through the window.

5 Do you have to work with glass manufacturers to incorporate the technology into a glazing? Yes we do – our expertise lies in antenna design, signal strength modelling and measurement. We partner with glass fabricators and work closely with them to incorporate our technology into their products. In the Finnish market, Pihla whose Antenna Glass window incorporates our technology, has been an important strategic partner for us. It is worth noting that we optimise our antennas by partner and product line, to maximise the benefits and ensure good fit with the production line setup.

6 Can you tell us about the testing process? How did you test it and what were the results like? We carry out both field trials and extensive lab testing in a controlled environment. We always start the testing procedure in our anechoic chamber (in lab conditions) where we can measure passive frequency responses of the windows under test, as well as to investigate the angular dependency of different designs at each frequency. Our field tests, on the other hand, aim to provide “real-life” results; a typical test would be a “beforeafter” setup inside a building where we replace a traditional window sash with a glass antenna sash, or alternatively suppress the operation of an already installed glass antenna sash with a microwave absorbing panel to block the signal. We then measure the indoor signal strength with a portable spectrum analyser to observe the improvement. To make the test as realistic as possible, we also use mobile phones to track the changes in the signal strength.

Across our field tests we have typically observed signal strength improvements ranging from nearly 10 decibels to as high as over 20 decibels in very

� The glass antenna reverses the window’s signal attenuation, enabling faster data speeds and better call quality indoors.

*Business Development, North America, Stealth Case, Finland http://www.stealthcase.fi

optimal conditions. For reference, a 10-decibel improvement means ten-fold increase in the signal strength and 20 decibels a hundred-fold increase. This can make quite a difference e.g., for 5G network download speeds!

7 What has feedback from potential customers been like so far? Based on the positive anecdotal customer feedback and the steadily increasing sales figures, we view the market reception as very positive! An exciting trend we have noticed recently is that construction companies (the largest customers) are starting to consider the glass antenna as a standard (rather than exception) feature for the windows they install on buildings. Since we aim for mass adoption, this is an encouraging development.

8 Do you have any background in glass before you launched this innovation? If so what? If not, what gave you the inspiration to work with glass? Our background was outside the glass industry, mainly in antenna design. The inspiration to work with glass came from the simple realisation that windows represent a natural entry point for wireless signals, along with natural light. We also discovered that adding our antennas to a window could be done as part of the fabrication process without disrupting the production line. This further reinforced our belief that window glass is great application area for our technology.

9 Does the technology work with all wireless providers or is it more suited to specific providers? Our technology works across the different operators since their mobile networks operate in the frequency band that our antennas are designed for. It is also worth mentioning that although we often discuss 5G in our test examples (it is the future, after all), our antennas benefit also the older mobile communication generations and types (3G and 4G) as well as first responder networks. �