| At the 2019 World Radio Conference,it was clarified that 137 GHz frequency band resources within 275 GHz to 450 GHz can be used for sixth generation mobile communications(6G),which means that the target frequency band of 6G should be above 275 GHz.After the operating frequency band of the signal enters terahertz,due to the high frequency,the signal introduces large losses during wireless transmission,resulting in a shorter transmission distance.To solve this problem,it is necessary to use a power amplifier to amplify the signal power to extend the transmission distance.This article focuses on the core devices in terahertz communication systems,and designs a power amplifier operating at 275 GHz based on the SiGe BiCMOS process.The main research work and innovation points are as follows:1.An embedding structure that can improve transistor gain has been proposed,which can generate resonance with the internal transistor at specific frequency points,thereby improving the transistor gain at specific frequency points.Through the combination of theoretical analysis and simulation calculation,it is clear that this structure can improve the transistor gain.Finally,based on this structure,the power unit of the power amplifier is designed.The simulation results show that the maximum power gain that can be achieved by the power unit of the drive stage and output stage is 10dB and 7.6dB respectively.2.A pre-embedding structure that can simplify the design of core inductors has been proposed.By changing the core inductor in the embedding to a 3-segment transmission line in the pre-embedding,the problem of complex core inductor design under the used process has been solved.Finally,a power amplifier with a working frequency of 275GHz was implemented using the proposed structure,completing the entire chip design process.The simulation results show that the power amplifier designed in this paper achieves a 20dB power gain,and the saturated output power is-4dBm.The simulation results show that the pre-embedding can solve the problem of low gain in terahertz power amplifiers,which has important guiding significance for the design of silicon-based terahertz amplifiers. |
