Liquid-Metal, Flexible-Ceramic-Based Antenna for Extreme High-Temperature Conformal Seeker Applications

High-performance hypersonic vehicles such as airplanes and rockets require electronics such as RF seekers that can operate in temperatures over 50°C. A major limitation for high-frequency electronics operating in extreme temperatures is that metals and dielectrics melt or have degraded material properties that are critical for the intended application. Here we demonstrate a high-frequency antenna using a nontoxic gallium alloy liquid as a conductor and a high-temperature resin matrix as a dielectric; these materials can operate at temperatures over 1000°C for extended periods. The liquid metal has high thermal stability and can maintain its liquidity up to 1300°C. The dielectric has an inhibited elastic stage and a more fully reactive ceramic stage, which allows conformal device fabrication in coordination with the fluidic conductor. The dielectric spectra of the uncured, semi-cured, and cured ceramics were measured from 50 MHz to 20 GHz. A liquid-metal ground meandered antenna that uses the ceramic as a substrate was prototyped and operated at 550°C for 30 minutes with no significant performance degradation. This antenna can be used in high-temperature environments such those experienced by RF seekers.