A scheme to enhance a wireless passive sensor's readout is presented. This alternative consists of the addition of a passive inductive-capacitive resonator placed between the sensor and readout antenna. A discrete model is proposed and used in simulations to study the effects of the resonator in the sensor-antenna interaction. A resonator was fabricated at 28 MHz to test the enhancement of the sensor's signal. Increases in the sensor's signal and the power transmitted to the sensor were always obtained for frequencies below 28 MHz. All experimental results were consistent with the simulation outcomes.