Thermally Resilient Microwave Switch and Power Limiter based on Insulator-Metal Transition of Lanthanum Cobalt Oxide

A microwave frequency series switch and shunt power limiter based on the insulator-to-metal transition (IMT) of sputtered LaCoO
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on sapphire is demonstrated for the first time. We demonstrate isolation >15 dBm and high linearity with >35 dBm OIP
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crossover at 125°C and 40Gbps signal throughput. The limiter achieves the highest power limiting over the broadest temperature range ever reported for an IMT material-based RF limiter, from 25°C to 125°C. It achieves low insertion loss <1 dB, flat leakage profile at 12 dBm output power and a variable threshold power between 15 to 19.5 dB, with turn-on time <20 ns. Additionally, we present a three-dimensional COMSOL Multiphysics model incorporating material temperature-dependent properties that accurately predicts LCO RF device performance up to 125°C.