The Development of Dual-band Bandpass Filter and 1.8GHz GaN HEMT Low Noise Amplifier

• Main Authors: Ping Wen Chiu, 邱炳文
• Other Authors: H. C. Chiu
• Format: Others
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/35650566529079388293

碩士 === 長庚大學 === 電子工程學系 === 98 === This thesis describes the design, implementation of dual-band band-pass stepped impedance filter and 1.8GHz AlGaN/GaN HEMT low noise amplifier. About the dual-band band-pass stepped impedance filter, it first was made by using frequency mapping to transform low-pass filter into band-pass filter and calculate the inductance and capacitance. And then, we used the structure of short-ended stepped impedance resonator to design the dual-band band-pass filter which the pass-bands (3.5GHz、5.8GHz) and bandwidths are controllable. This filter has the characteristic of wide bandwidth. The 1.8GHz low noise amplifier was designed by using AlGaN/GaN high electron mobility transistor. There are two stages in the amplifier. I did my best to reduce the noise figure in first stage and increase the output gain in second stage. A 50Ω low-pass filter matching networks was used for input terminal. Two suitable high-pass matching filters are applied for intermediate and output terminals. A high gain and a low noise performance were obtained for AlGaN/GaN HEMT LNAs.