本論文研究應用於Ku-Band及24GHz之超寬頻低雜訊放大器(Low Noise Amplifier, LNA),電路採用穩懋半導體公司(WIN) 0.15μm pHEMT 製程進行設計。論文總共利用三種架構進行放大器之設計,包括負回授式放大器,共源級電感退化式,以及電流再使用式架構。並對三種放大器之設計進行分析比較。 首先設計一個3-10GHz的寬頻低雜訊放大器,主要架構為負回授式放大器。其特性為可以提供平坦增益,以及好的輸入阻抗匹配,並增加了放大器電路的穩定性。此低雜訊放大器所獲得之增益為19.5dB~22.3dB,雜訊值為6.7dB~7.7dB,輸入返回損耗為-12.9dB~-14.3dB,輸出返回損耗為-10.1dB~-22.5dB,反向隔離度為-36.9dB~-39.8dB。 第二部份主要設計一個可應用於衛星小型地面站(Very Small Aperture Terminal),也就是VSAT系統中之Ku頻段的低雜訊放大器。主要是利用共源級電感退化式架構進行電路設計,以獲得較好的輸入匹配,較大功率傳輸和最小雜訊的特性。此低雜訊放大器所獲得之增益為11.67dB~17.94dB,雜訊值為1.454dB~2.479dB,輸入返回損耗為-29.39dB~-35.44dB,輸出返回損耗為-12.86dB~-20.73dB,反向隔離度為-20.44dB~-27.99dB。 最後設計一個24GHz的低雜訊放大器,可應用在車用雷達系統上,而選用的基本架構為電流再使用式架構 (Current-reused technique)。此架構可以提供高增益、降低供應電壓和消耗功率。此低雜訊放大器所獲得之增益為8.94dB,雜訊值為2.308dB,輸入返回損耗為-11.67dB,輸出返回損耗為-10.93dB,反向隔離度為-23.11dB。
This thesis presents the design of ultra-wideband low noise amplifier (LNA) using WIN 0.15μm pHEMT process to design the circuit. Three frequency bands in the range of 3 GHz to 24 GHz were conducted. The LNAs adopted three kinds of configuration in this thesis. They are resistance feedback amplifier, source inductor degeneration and current reused technique. At first, a 3-10GHz low noise amplifier was designed. The adopted structure is the resistance feedback amplifier, which provides a flat gain, a good input impedance match and better stability condition for the amplifier circuit. This low noise amplifier achieves the following characteristics: gain 19.5dB~22.3dB, noise figure 6.7dB~7.7dB, input return loss -12.9dB~-14.3dB, output return loss -10.1dB~-22.5dB, and isolation -36.9dB~-39.8dB. In the second part, a Ku-band low noise amplifier was designed for the very small aperture terminal. The circuit structure is the source inductor degeneration, which provides a good input impedance match, high power transmission and low noise. This low noise amplifier achieves the following characteristics: gain 11.67dB~17.94dB, noise figure 1.454dB~2.479dB, input return loss -29.39dB~-35.44dB, output return loss -12.86dB~-20.73dB, and isolation -20.44dB~-27.99dB. Finally, a 24 GHz low noise amplifier is designed for a vehicular radar system. The structure of current reused technique was chosen which gives a high gain and low supply voltage and power consumption. Simulated data show that this low noise amplifier has a gain of 8.94dB, noise figure 2.308dB, input return loss -11.67dB, output return loss -10.93dB, and isolation -23.11dB.