A common-gate bootstrapped CMOS rectifier dedicated for VHF (very high frequency) isolated DC-DC converter is proposed.It uses common-gate bootstrapped technique to compensate the power loss due to the threshold voltage,and to solve the reflux problem in the conventional rectifier circuit.As a result,it improves the power conversion efficiency (PCE) and voltage conversion ratio (VCR).The design saves almost 90％ of the area compared to a previously reported double capacitor structure.In addition,we compare the previous rectifier with the proposed common-gate bootstrapped rectifier in the case of the same area;simulation results show that the PCE and VCR of the proposed structure are superior to other structures.The proposed common-gate bootstrapped rectifier was fabricated by using CSMC 0.5 μm BCD process.The measured maximum PCE is 86％ and VCR achieves 77％ at the operating frequency of 20 MHz.The average PCE is about 79％ and average VCR achieves 71％ in the frequency range of 30-70 MHz.Measured PCE and VCR have been improved compared to previous results.