High Frequency Gain Block Based On SiGe HBT

The technology of SiGe HBT is based on the Si technology, So the device technology is very mature and also with low price. Its power additive efficiency can reach to 70%, the same to the MESFET, it's the most overhang merit is that it has so low phase noise.Owing to its outstanding frequency character, temperature character and radioresistance character, what's more, it also can be compatible with traditional Si technology, it gets the most fast development in the electron technology field within 20 years. Belong to this technology's improvement and development, SiGe technology is being selective performance flat that make the admixture signal transmit system come true.In this paper, We firstly introduce the basic concept of this topic, and study the important data of SiGe HBT, mainly including characteristic frequency, maximum general frequency, the current of collector anode, the current of base and its gain. We also simply introduce the basic structure of the SiGe HBT, mainly including mesa structure, multicrystal silicon emitter GeSi HBT structure and self aligned structure.The main data of high speed bipolar transistors are current gain, positive-going transition time or barrier frequency, maximum general frequency and digital electronic gate late timing, also contain noise coefficient, early voltage et al. current gain, barrier frequency and noise coefficient play an very important role in the application of the high frequency micro wave; positive-going transition time must be made very low in the digital circuit; current gain and early voltage'product must be very high in the mimic buses. Those data can infect each other sometimes, so that, there are some difficult in the design and optimize of the circuit. In the fact technology, we use the study result to optimize the characters of the devices.Through the application and study of the high frequency circuit system, we design a new kind of the structure of SiGe HBT amplification system which based on the structure of the Darlington, in the same time, we also improve the power ability of the SiGe HBT.Against the problems in the traditional SiGe HBT device , we use the buried layer metal self aligned technology, optimizing the technology flue. We introduced the fabrication method of the film resistor, based on it, we use ADS software flat to do simulation on the device.In the end, we have designed the layout of the high frequency gain module.