Abstract: The output voltage level of the limiter for protecting the RF front-end from physical damage is difficult to reduce, and often leads the low noise amplifier to enter into deep saturation, disturbing the normal function of the receiving channel. To solve this, we introduce a high isolation and nanosecond response RF front-end active limiter module with key technology of parameter design and measurement. The proposed limiter module is made up of an integrated detector, high-speed comparator and multi-stage PIN diode. The saturation impedance of the limiter module is degraded on a large scale and the isolation is increased remarkably. In this way, the leakage power level to the later sensitive module is reduced and the receiver is prevented from entering deep saturation.