Low insertion loss microplasma-based limiter integrated into a microstrip bandpass filter

The use of microplasma discharges as power-induced limiter elements in microstrip devices is proposed to protect receivers against highpower microwave threats. A microstrip bandpass filter integrating such a microplasma-based active microwave power limiter has been designed and measured. Power limitation is observed when the input power exceeds 19 dBm with a leakage power of 14 dBm. Due to the gaseous properties of the active medium, the proposed structure exhibits a very low additional insertion loss of 0.06 dB.