A 8-12GHz 4-Element SiGe BiCMOS Multi-Function Chip for Phased Array Systems

This paper presents a 4-element X-band multi-function chip(MFC) based on SiGe technology, which includes RF switches, low noise amplifier, power amplifier driver, attenuator, phase shifter, Power divider and digital beam forming. The traditional MFC 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 amplifier parallel peaking, arc adopted to achieve better temperature characteristics, smaller attenuation additional phase shift and broadband characteristics. The test results show that the MFC works at 8-12GHz, RMS phase error is less than 3.5 degrees, attenuation additional phase shift is less than 3degrees, the RX gain and TX gain is 10dB and 3dB, respectively. The gain variation is less than 0.019dB/oC. The size of the chip contains pad is about 6mm*9mm.