Supercritical carbon dioxide foaming to fabricate low loss air material for high performance antenna

With the rapid development of 5 G and the anticipated transition to 6 G, the demand for high-performance antennas has grown significantly, placing greater emphasis on the role of low-dielectric materials in enhancing radiation efficiency. To date, supercritical carbon dioxide (scCO₂) foaming is one of the most effective methods to fabricate "Air Material"with ultra-low dielectric performance. This study investigates the Air Material, developed via scCO₂ foaming, as substrates for high-performance antennas. Patch antennas were fabricated using Air Materials and its performance was evaluated through simulations and experiments. By comparing antenna using conventional substrates, which are FR-4 and Rogers RT/duroid 5880, the gain and efficiency of antenna made of Air Material are capable to maintain a high gain and high efficiency of 8.78 dBi and 93.25 % respectively, while the other two are difficult to achieve a gain of 7 dBi and an efficiency of 67 %. Furthermore, in Wi-Fi applications, the average annual energy consumption of the antenna made of Air Material is less than 40 % of the FR-4 antenna, and about 70 % of the Rogers RT/duroid 5880 antenna. The results highlight the potential of scCO₂ foaming technology for advanced Air Material in the application of high-performance antenna, and opens a technologically viable pathway for designing next-generation communication material.