As the battlefield environment becomes increasingly complex, especially in high-confrontation environments, it poses a great threat to all types of existing equipment. This article designs a C-band radar receiver protector, which adopts the structural design of inflatable microwave switch tube + waveguide coaxial conversion, innovatively integrates the solid-state limiter chip into the waveguide coaxial convertor, while the limiting chip adopts a cascaded form to increase the power of the microstrip limiter. With a power resistance of over 10 MW and a response time of less than 5 ns, the protector is not only used for receiver protection during radar transmission, but also can cope with external electromagnetic interference and high-power microwave attacks.