.40-50ghz Indium Phosphide Monolithic Integrated Low-noise Amplifier

This graduate thesis introduces the design of a 40-50GHz InP MMIC LNA. This project is key part of the new generation cryogenic radio astronomical telescope research project, sponsored by Japan national astronomical observatory, carried out together by Ammsys Inc. and Honjo's Lab of UEC. The project targets the latest technology and specification in the world. InP 0.1μm HEMT process provided by NTT Electronics (NEL) is used, with CPW as transmission line.The author was involved in most of the research work during his exchange in Japan. The circuit has been fabricated and tested, however due to contract limitation, the circuit over all test result is confidential, thus unable to be used in this thesis. But test results of InP HEMT sample chip and all the individual passive fabricated components are used here. All those test results that are used in this thesis were tested by professional testing engineer in the lab, and testified by third party test results, thus the accuracy is guarrenteed.Modeling of passive components in InP process. Based on measurement results, CPW under-bridge structure is studied carefully, and its accurate equivalent circuit model and the novel under-bridge even mode impedance matchning method are proposed; its odd mode suppression capability is also studied. Meanwhile, analytical and EM simulation models are also built for those components that will be used in this MMIC LNA, including short stubs and passive extrinsic configuration of InP HEMT.Small signal model parameters extractions of InP HEMT. With the help of'simplified three steps method'and modified FET Noise Model Gupta, the passive parasitic parameter part and the intrinsic part of the small signal model are created respectively. Based on measurement results, firstly extrinsic and then intrinsic parameters of HEMT are extracted. As an important theoretical foundation of LNA, Noise theory and models are introduced first, then noise model parameters are extracted based on measurement results.Optimization of InP HEMT extrinsic configuration. A large amount of parasitc parameters are introduced by HEMT extrinsic structure in CPW mode, which is effectively optimized in this thesis. Based on the HEMT small signal model that has already been built, classical circuit theories are introduced into the optimization of HEMT extrinsic configuration, for better noise figure and stability.LNA circuit design. With those passive and active models testified by measurements, two stages of LNA is designed with high precision. The first stage is matched with optimum noise, the second optimum power. Simulation result realizes the room temperature goal specifications, and according to estimation, the cryogenic condition result can also reach its goal specs. Finally, DC bias and layout arrangement is done.Simulation result of over all specifications: in the frequency band of 40-50GHz, @ room ambient temperature (300K), Noise Figure< 2.5 dB, Gain> 15dB; @ Cryogenic ambient temperature (20K), Noise Temperature<25K, Gain> 20dB.