PIN 다이오드로 동작되는 보조경로를 갖는 저잡음 증폭기
LNA having redundant path operated by PIN diodes switching
- 발행기관 아주대학교
- 발행년도 2006
- 학위수여년월 2006. 2
- 학위명 석사
- 학과 및 전공 산업대학원 정보전자공학과
- 본문언어 영어
초록/요약
A quarter and half wavelength stub useful in designing microwave circuits could substitute mechanical relay switches. Impedance circle repeating 0 and ∞ Ω by the terminated impedance on the transmission line can change the direction of microwave signal flowing along the transmission line. The terminated impedance can be determined from PIN diode impedance state by bias current. This stub switch can reduce the noise figure as much as 0.6dB of two mechanical relay switches in noise-sensitive wireless communication system and secure higher reliability.
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Contents
Abstract
Figures contents
Ⅰ Introduction ···························································· 1
Ⅱ Theoretical analyses and applications ····················· 3
Ⅱ. 1 Properties of one-quarter and one-half wavelength transmission lines ···························· 3
Ⅱ. 2 Curves for input impedance terminated in a short or an open ························································· 5
Ⅱ. 2. 1 Input impedance to an open-terminated line ··························································· 5
Ⅱ. 2. 2 Input impedance to an short-terminated line ···························································· 8
Ⅱ. 3 Realization of switching system using a open-short shunt stub ··············································· 10
Ⅲ Simulations and fabrications ·································· 16
Ⅲ. 1 LNA Design ··················································· 17
Ⅲ. 1. 1 Biasing circuit design ···························· 18
Ⅲ. 1. 2 Protecting from oscillation by feedback through redundant path ······························ 20
Ⅲ. 1. 3 Schematic and simulation ······················ 21
Ⅲ. 1. 4 Reviewing simulation results ················· 25
Ⅲ. 1. 5 Reviewing test results ··························· 28
IV Conclusions ·························································· 35
References ··································································· 36
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Figures contents
Figure 1. 1 Microwave signal flow on the main path and redundant path of Tower Top LNA by open-short shunt stub switching circuit. ················································· 2
Figure 2. 1 (a) Voltage and current wave distribution when the transmission line is terminated by an open. (b) Impedance distribution along with a transmission line terminated by an open. ················································ 6
Figure 2. 2 (a) Voltage and current wave distribution when the transmission line is terminated by a short. (b) Impedance distribution along with a transmission line terminated by a short. ················································· 8
Figure 2. 3 Switch circuit using open-short shunt stub. (a) Input switching circuit. (b) Output switching circuit ···· 10
Figure 2. 4 Equivalent circuits for a PIN diode. (a) Reverse bias state. (b) Forward bias state. ······························ 13
Figure 2. 5 Simplified equivalent circuits for the series and shunt PIN diodes. (a) Series connected PIN diode. (b) Shunt connected PIN diode. ······································· 15
Figure 3. 1 Loss budget for each stage of LNA calculated by AppCAD NoiseCalc. ·············································· 18
Figure 3. 2 Amplifier biasing schematic. ························ 20
Figure 3. 3 Schematic for Tower Top LNA. ··················· 23
Figure 3. 4 Simulation schematic for Tower Top LNA. ·· 24
Figure 3. 5 Simulation results for the gain and noise figure in S parameter while directed to main path. ··············· 26
Figure 3. 6 Simulation results for the gain and noise figure in S parameter while directed to redundant path. ······· 27
Figure 3. 7 Picture of the Tower Top LNA. ··················· 29
Figure 3. 8 Picture of quarter-wave open-short stub switch for Tower Top LNA. ·················································· 30
Figure 3. 9 Test results for the gain and noise figure in S parameter while directed to redundant path. ·············· 31
Figure 3. 10 Test results for the gain and noise figure in S parameter while directed to redundant path. ·············· 32
Tables contents
Table 3. 1 Major design parameters of Tower Top LNA for Node B. ····································································· 16
Table 3. 2 Description for features of components. ······· 21
Table 3. 3 Measured results of the Tower Top LNA. ····· 34
