Successful 47% Weight Reduction of NTN Flat Antenna through Innovative Heat Dissipation Device Design

【Key Points】

Achieved 47% weight reduction of flat antenna for NTN through innovative heat dissipation device design

Integrated a newly designed heat dissipation device using advanced composite materials into the NTN flat antenna and confirmed required electrical characteristics

Verified operational functionality as a satellite communication user terminal composed of the lightweight flat antenna and modem

Enabled integration of satellite communication user terminals onto diverse mobility platforms such as drones and vehicles, significantly contributing to NTN realization

The National Institute of Information and Communications Technology (NICT, President: Hideo Ohno), Sharp Corporation (Sharp, CEO: Tetsuji Kawamura), Mitsubishi Chemical Corporation (Mitsubishi Chemical, President: Manabu Tsukamoto), and TECHLAB Co., Ltd. (TECHLAB, Representative Director: Hirofumi Hatakeyama) have jointly succeeded in reducing the weight of a flat antenna for NTN (Non-Terrestrial Network) (*1) by 47% (from 5.5kg to 2.9kg).

By integrating a newly developed "CFRP (*4) heat dissipation device"—made from a novel composite material combining carbon fiber prepreg (*2) and graphite sheets (*3) that offers both lightweight properties and high thermal conductivity—into the NTN flat antenna, significant weight reduction was achieved. The necessary electrical characteristics for the flat antenna were also confirmed. Furthermore, operational functionality was verified as a satellite communication user terminal including the modem.

This achievement realizes substantial weight reduction, achieving a weight within the payload capacity of widely used industrial drones. By enabling a lighter user terminal that can be directly mounted and operated, the range of applicable mobility platforms such as drones and vehicles has been significantly expanded. This advancement greatly contributes to NTN realization by enabling communication line establishment in mountainous and disaster-stricken areas, real-time transmission of mobility location data, and applications in autonomous driving.

【Background】

Satellite communication via NTN enables high-speed connectivity even in environments where terrestrial mobile communication is difficult, such as mountainous regions, at sea, on remote islands, or in disaster zones. However, flat antennas for NTN satellite communication user terminals require high heat dissipation performance (thermal conductivity) due to significant heat generation from the need to track satellites or HAPS (*5). Additionally, ultra-miniaturization and weight reduction of flat antennas are essential to mount satellite communication user terminals on diverse mobility platforms. To date, the four organizations have jointly researched and developed materials with excellent thermal conductivity and lightweight properties, as well as design, molding, integrated design, and evaluation of heat dissipation devices, advancing the miniaturization and weight reduction of flat antennas for satellite communication user terminals.

【Achievements】

This time, NICT, Sharp, Mitsubishi Chemical, and TECHLAB jointly achieved a 47% weight reduction of the NTN flat antenna through innovative heat dissipation device design. In this achievement, NICT addressed the weight and thermal conductivity limitations of aluminum heat dissipation devices in flat antennas, established design guidelines for lightweight heat dissipation devices, and conducted R&D on the composition and device structure of the new composite material used in this project (see Figure 1).

Figure 1 Structure of heat dissipation devices using different materials: Left: Aluminum, Right: Composite material

Mitsubishi Chemical developed the carbon fiber prepreg and graphite sheet materials that constitute the composite, while TECHLAB established the design and molding technology for heat dissipation devices using these composite materials. This enabled the fabrication of a "CFRP heat dissipation device" that leverages the lightweight and high thermal conductivity properties of the materials, achieving a weight of less than 1kg for the heat dissipation device alone. Sharp then integrated this CFRP heat dissipation device into the flat antenna, successfully achieving a 47% weight reduction (5.5kg → 2.9kg) (see Figures 2 and 3). Antenna characteristic evaluations confirmed that the difference in transmission patterns falls within terminal error margins and that there is no difference in reception gain characteristics.

Furthermore, the developed NTN flat antenna was integrated with a modem and other components, and operational functionality as a satellite communication user terminal was confirmed. By realizing a lighter terminal that can be directly mounted and operated, the range of applicable mobility platforms such as drones and vehicles has been greatly expanded.

Figure 2 Developed NTN flat antenna (approximately 45cm square): Left: Front view, Right: Rear view

Figure 3 Conceptual configuration of the satellite communication user terminal integrating the heat dissipation device, NTN flat antenna, and communication modem

【Future Outlook】

Going forward, further detailed evaluations of heat dissipation performance and mountability will be conducted, along with research into optimal heat dissipation device designs tailored to terminal configurations and applications. Prototype development and verification will continue toward the practical application of ultra-compact, lightweight satellite communication user terminals designed for mobility platforms, aiming for future realization of NTN.

＜Roles of Each Organization＞

・NICT: Overall design and simulation of the flat antenna including the heat dissipation device, and investigation of weight reduction strategies

・Sharp: Development and integrated evaluation of the NTN flat antenna (satellite communication user terminal)

・Mitsubishi Chemical: Material development of carbon fiber prepreg and graphite sheets used in the heat dissipation device

・TECHLAB: Design and molding processing (device formation) of CFRP using carbon fiber prepreg and graphite sheets

＜Related Past Press Releases＞

・July 30, 2025 Sharp Corporation: "Mitsubishi Chemical, NICT, and TECHLAB Agree to Jointly Develop Ultra-Compact, Lightweight Satellite Communication Terminals for Mobility"

https://corporate.jp.sharp/news/250730-a.html

・July 30, 2025 Mitsubishi Chemical Corporation: "Mitsubishi Chemical, Sharp, NICT, and TECHLAB Agree to Jointly Develop Ultra-Compact, Lightweight Satellite Communication Terminals for Mobility"

https://www.mcgc.com/news_release/pdf/02408/02662.pdf

＜Glossary＞

*1 NTN (Non-Terrestrial Network): A communication network using satellites or high-altitude platforms, as opposed to terrestrial networks.

*2 Carbon Fiber Prepreg: A sheet-like material in which resin is pre-impregnated into carbon fibers, used to manufacture lightweight and high-strength composite materials.

*3 Graphite Sheet: A material made by thinning graphite into a sheet form. It has high thermal conductivity, heat resistance, and flexibility, and is used as a heat dissipation or sealing material in electronic devices and industrial applications.

*4 CFRP (Carbon Fiber Reinforced Plastic): A composite material made of carbon fiber-reinforced plastic, known for being lightweight with high rigidity and strength.

*5 HAPS (High Altitude Platform Station): An aerial base station-type communication platform using unmanned aircraft or airships that remain in the stratosphere.

※ The content of this news release is accurate as of the date of announcement.

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