The letter comprises an analysis of nonlinear coupled resonant circuits for application in limiting low power microwave signals. It presents a novel approach to the use of the resonant circuit containing a nonlinear element which concerns obtaining power dependence of the quality factor and transmission losses without tuning resonant frequency. The basic theory of the single circuit is presented and examples provided of simulations in Microwave Office and measurements results of the designed two-stage limiter. The effect of transforming the input signal amplitude causes this type of circuit to be power-sensitive and allows to limit low power signals.