Abstract: An X band multi-function chip based on SiGe technology, including RF switches, low noise amplifier, power amplifier driver, attenuator and phase shifter is presented in this paper. The traditional multi-functional chip is realized by GaAs process, which has the disadvantages of high cost and low integration. This design is based on SiGe process, which greatly reduces the cost of the chip and improves the integration. A series of techniques, such as on-chip temperature compensation, phase compensation and parallel peaking, are adopted to achieve better temperature characteristics, smaller attenuation additional phase shift and broadband characteristics. The test results show that the multi-functional chip works at 8 GHz~12 GHz, RMS phase error is less than 3°, attenuation additional phase shift is less than 2. 5°, the RX gain and TX gain is 10 dB and 3 dB, respectively. The size of the chip contains pad is about 12. 6 mm2. With the same performance as GaAs process, the chip area is reduced by more than 30??, and the cost can be greatly reduced.