.4-8ghz Low-noise Amplifier Developed

Based on the advanced thin-film hybrid integrated circuit technology, using Al2O3 fine ceramic substrates with high finish, good heat-conductivity and better mechanical strength, a C-band low noise amplifier is designed in this paper applying the eutectic technology and advanced stick techniques of Seekon Company.In this paper, the broadband balanced form circuit and low-noise, high-electron mobility tube-and-stem FHX45X of Fujitsu Company is used. 3-dB-coupler is designed independently through the small-signal modal S-parameter method. By matching the input and output parts of the circuit, the amplifier works in the low noise high gain area. Simulation results are obtained by ADS simulation software of Agilent Company and the circuit board wiring is realized in AutoCAD. In order to ensure the successful accomplishment of eutectic technology process, ridge-shaped carrier is used and the input and output parts of the circuit are designed individually.The amplifier chip and cascading chip designed in this paper are measured by measurement instruments of HP series including HP8757D Scalar Network Analyzer, HP E8247C Signal Generator, 8259L Spectrum Analyzer and 8970B Noise Figure Analyzer.When measure, an extra 12V DC supply is applied to the 4GHz-8GHz low noise amplifier. The supply is converted to a 2V stabilized voltage supply inside the amplifier and the current is 190mA. The measured results are as follows:Nf ≤ 2.18dB (Satisfy the demand of Nf≤ 2.2dB)34.65dB≤G≤38.75 dB (Satisfy the demand of 32dB≤G≤39dB)ΔG=±2.05dB (The demand of |ΔG|≤4dB is nearly satisfied)VSWR1,2<1.86 (Satisfy the demand of VSWR1,2<2)P-1(dBm)≥10.8dBm (Satisfy the demand of P-1(dBm)>10dBm)Although there are some shortcomings in the amplifier design, the research work is generally completed. The study of this paper is related to a fore-research project of Seekon Company, and this project is complete by myself independently.