Research Of Low Noise Amplifier For Receiving System Of Meteorological Radar

With the wide applications of meteorological radar in weather forecasting,agriculture,transportation and other fields,it has changed people's way of life,and greatly improved our live quality and production efficiency.As the first active device after antenna of meteorological radar receiving system,Ku-band low noise amplifier?LNA?has a very important effect on the performance of meteorological radar system.However,the current Ku-band LNAs are mostly designed and fabricated in III-V compound process,which has high cost and poor compatibility.With the continuous scaling of CMOS process,design of Ku-band LNA based on CMOS technology becomes one of the hot topics in the field of radio frequency.To satisfy the demand of meteorological radar receiving system for Ku-band LNA,works about LNA topology,impedance matching and noise optimization have been carried out in this thesis,and the main contents are as follow:1.A cascaded LNA composed of broadband resistive negative feedback cascode structure,source follower and inductance peaking cascode stage was proposed based on UMC 0.18?m CMOS technology.After analyzing the circuit performance,complete layout and post layout simulation were carried out.Simulation results shown that the center frequency of LNA with resistive negative feedback is 14GHz,and the noise figure reaches the minimum value of 3.3 dB at 14.8 GHz,with a variation of 0.6 dB within the working frequency band.Moreover,the scatter parameter simulation result indicated that the bandwidth is 12GHz-15.3GHz and the gain achieves a maximum value of 21.5 d B at 14 GHz.The input 1-d B compression point?IIP₃?is-7dBm,indicating the LNA with resistive negative feedback has a good linearity.2.Based on TSMC 0.18?m CMOS process,a novel LNA cascaded by active self-biased source inductance degradation cascode and common source structure fed back by a source current with inductance peaking technique.At the same time,bond wire was used as inductors of the circuit,and bond-wire inductor is analyzed through simulation.The simulation results of post layout shown that the minimum value of NF is 2.9dB,and the maximum value about 3.9d B appears at 16GHz with a slight variation of 1dB.The measured maximum value of S₂₁ is 8.8dB at 13.86GHz,while the simulation results of 14.88dB at 14.6GHz was achieved.The measured S₁₁,S₂₂ and S₁₂is respectively lower than-10dB,-9dB,and-32.5dB.The measurement results of S-paramter are basically consistent with simulation results,indicating the ratinality of the proposed design.