Measurement of radio signal propagation through window panes and energy saving windows

Abstract

Abstract-Glass windows have undergone an energy saving evolution over the past three, four decades, from single panes till today's ultralow-emission windows. While the earliest energy saving windows were constructed as a sandwich of clear glass panes using the vacuum-flask principle, modern low-emission windows includes panes with coatings of metal and/or metal oxides. This coating has caused radio propagation problems for communication systems; something that may be utilized to protect a building from intentional electromagnetic interference

Measurement of Attenuation by Building Structures in Cellular Network Bands

“…A maximum attenuation of around 50 dB is observed for window1 (V-V polarization) and window3 (H-H polarization). At frequencies falling within the studied band in this latter, maximum attenuation has been found for modern windows of: 60 dB in [4]; 38 dB in [5]; 22 dB in [6]; and 36 dB in [7]. These results also indicate the high losses which the contemporary windows introduce.…”

“…However, new windows have sophisticated frames with several thick glass panes. This construction together with metal coating of the glasses aims to achieve good thermal isolation (high energyefficiency) by reflecting the infrared radiation and to prevent the ultraviolet part of the spectrum to enter the building [4], [5]. At present, information about the loss introduced by these advanced windows is even more important than before.…”

“…The reason is that the façades of the modern office buildings, where multiple mobile users are located, consist mostly from windows. It has been shown that modern windows introduce higher attenuation than the old ones [4], [6]. Other works studying the loss for contemporary windows can be found in [5], [7].…”

Minimization of shielding effectiveness of energy saving windows in WiFi frequency range

“…In order to estimate the dependence of SE on the gap between the glass panes, measurements of Low-E windows were performed in an anechoic chamber. There are several other methods for measuring SE which include either close proximity experiments [7,10] or measurements in a reverberation chamber [7,19]. The former method has a high measurement error because multiple reflections occur between antennas standing tenths of centimetres from each other.…”

“…An in-depth theoretical analysis on single, double and laminated shields was made by Schulz et al in 1988 [6]. It was found that these coatings can attenuate microwaves up to 50 dB in a range of 1 to 12 GHz frequency [7][8][9]. This means that mobile communication frequencies, GPS and WiFi, can be highly attenuated by Low-E windows [2,10,11].…”