Abstract: Microwave transmission line and a 7.5-8.5GHz 4 bit digital phase shifter are designed and fabricated on high-resistivity silicon（HRS）.The insertion loss of the 50Ω transmission line is below 0.8dB/cm in the range of 5-15 GHz,which demonstrates that high-resistivity silicon can be used as the microwave substrate.Furthermore,the measured results of the 7.5-8.5GHz phase shifter shows that the insertion loss is（7.5±3）dB and the return loss is above 12dB.The RMS phase accuracy is less than 5°.