Energy saving glazing with a wide band‐pass FSS allowing mobile communication: up‐scaling and characterisation

Abstract

A real case study and characterisation of modern energy efficient windows allowing mobile communication is presented. An earlier study had shown that laser scribing of energy saving coatings allows highly reducing the microwave attenuation (from 30 to 1-3 dB) using a wide band-pass frequency-selective surface (FSS) while preserving the thermal quality of the window. To achieve large-scale production, the laser scribing technique has been further developed. The effect of laser scribing on the mechanical properties of a substrate has been determined through mechanical strength tests. Moreover, the insulating properties of the window have been analysed to ensure the reliability of this technology. As a real case demonstration, an entire train has been equipped with prototype windows. The signal quality has been controlled for a wide band of frequencies and for existing technologies such as long term evolution, universal mobile telecommunication system, multiple input multiple output and for different configurations such as a stationary and a moving train.

Performance Assessment of a nZEB Carbon Neutral Living/Office Space and Its Integration into a District Energy-Hub

“…An intensive use of daylight and passive solar gains is achieved within the unit, besides reaching a positive energy balance over the whole year through 'on-site' generation of solar power and heat. The SolAce unit comprises multifunctional facades involving several novel technologies developed by the research group of Nanotechnology for Solar Energy Conversion at EPFL Solar Energy and Building Physics Laboratory: this includes nanotechnology-based glazing for solar photovoltaic modules [13] and solar thermal collectors [14], innovative micro-structured glazing providing seasonal dynamic management of daylight and solar gains [15,16], and insulating triple glazing with laser-engraved special low emissivity (low-e) coatings for enhanced telecommunication signal transmission [17,18] (Figure 2d). Advanced building sensing and control technologies interact with façade elements and the indoor environment: fostering human-building interaction (HBI), they provide a user-centric approach favoring users' visual and thermal comfort.…”

“…Overall, considering that the current global building stock is estimated at more than 220 billion m 2 , with a yearly growth of 5.5 billion m 2 , the world will count approximately 415 billion m 2 of built area in 2050 [8]. As such, despite the reduction in carbon emissions of the building stock by 30% since 1990 in Switzerland due to efficiency measures and renewables integration [9], the cited efforts seem inadequate to reach the carbon neutrality of the building sector worldwide by 2050, the current NZEB stock being estimated at less than 1% of all buildings on Earth [10] (p. 18).…”

Delivering Gigabit Capacities to Passenger Trains: Tales from an Operator on the Road to 5G

“…In modern railway cars, the window panes have a thin metallic coated layer for enhanced thermal (infrared) insulation. However, such a metallic coating increases the RF transmission loss through them significantly (e.g., 25 − 30 dB [1]). Recently, by adjusting the coating pattern on the window panes, engineers have successfully reduced the transmission loss for sub 3 GHz bands to only a couple of dBs.…”

“…Recently, by adjusting the coating pattern on the window panes, engineers have successfully reduced the transmission loss for sub 3 GHz bands to only a couple of dBs. Simulations and measurements of railway cars equipped with RF transparent windows in real conditions demonstrated a reduction of around 12 − 14 dB at 1.8 GHz band [1], [13]. Using frequency selective surface concepts in electromagnetics, scientists are expected to come up with an improved coating pattern which could likewise serve to reduce the transmission loss for frequency ranges up to 6 GHz.…”

“…The first is associated with the major strategy used by service providers and railway operators to provide connectivity to train users by deploying on-board equipment, for instance, signal repeaters, or Wi-Fi routers backhauled via the cellular network. This strategy is threatened in two ways: (1) The use of multiple-input multiple output (MIMO) systems popularized in 4G and improved in fifth generation systems (5G) with higher order MIMO, the use of both time-division duplexing (TDD) and frequency-division duplexing (FDD) in 5G, and the use of millimeter-wave spectrum in 5G, dramatically increasing system complexity and cost for on-board equipment;…”