ABSTRACTA broadband high‐efficiency radio frequency (RF) rectifier with second harmonic suppression function working at 1.8 GHz is proposed in this study. The higher harmonics of the rectifier are suppressed by the harmonic suppression network, and the L‐type impedance matching structure is used to complete the impedance matching. Measurement results clearly illustrate the outstanding performance of the rectifier. To be more specific, when the load resistance stands at 1.4 kΩ and the input power is 0 dBm, the rectifier exhibits an even more remarkable conversion efficiency. In the frequency band ranging from 1.1 to 2.5 GHz, the conversion efficiency exceeds 40%. When the input power reaches 8 dBm, the operational frequency range from 0.8 to 2.5 GHz (a bandwidth of 103%), with an efficiency exceeding 50%. Moreover, across an input power range from −2 to 18 dBm, the rectifier maintains an efficiency of over 50%. In terms of physical dimensions, the rectifier measures merely 34 × 19 mm2.