X-band PIN diode limiter with low spike leakage performances using re-entrant coaxial cavity

This paper describes a design methodology and the experimental results of an X-band two-stage PIN diode limiter, whose leakage output powers have been successfully suppressed by optimizing the size of multi section re-entrant cavities. The optimized re-entrant cavity provides an appropriate impedance for the PIN diodes in order to achieve moderate limiting performances. The fabricated limiter exhibits a low spike leakage of 21.6 dBm and flat leakage of 20.7 dBm with a high isolation of more than 48 dB at 12.5 kW input power.