This paper presents a low power 2.4 GHz receiver front-end design in 0.18 μm CMOS using a resonator coupling technique. An on-chip transformer combined with the parasitic capacitances from the LNA, a mixer, and the transformer itself comprises the resonator coupling network (RCN). Without any power consumption, the RCN not only acts as a balun, but also provides passive gain to suppress the noise from the mixer. The measured voltage conversion gain, input return loss, and IIP3 are 27.8 dB, 14 dB, and -23 dBm, respectively. The noise figure is 5.4 dB at the IF frequency of 100 kHz. The power consumption is only 1.92 mW under a supply voltage of 1.2 V. The required LO power is only -9 dBm. With such a low LO power level, the receiver front-end including the VCO is expected to consume less power, which is truly suitable for the wireless sensor network applications.