电子科技大学：《无线系统中的微波与射频 Microwave and RF Design in Wireless Systems》课程教学资源（课件讲稿）ch04 Antennas and Propagation for Wireless System

To conclude -1 ●●● ●●●● ●●●●● ●●●0 3.5 Noise Temperature and Noise Figure ●●●●0 ●●● No larger noise DUT N;=kToB- kB GkB G,Te,B small noise F=S./N=1+T=1+ S。/N。T Lossy Line: y=a+jB,L=e2l T.-(L-IyT F-1+(-D Cascaded Components =+会++ 十 GGG2GGG; F=F+ E-1F-1F4-1 十 GGG,GG,Gs 3.6 Noise Figure of Passive Networks N =kTB Ga-G. IS2Pa-r,P) T= 1-1 ① 11-Sr,P(1-Im) (S] (T) +1-G1T F=1 S2S2T G21 To 1-Sur 1

To conclude - 1 §3.5 Noise Temperature and Noise Figure §3.6 Noise Figure of Passive Networks larger noise small noise Lossy Line: Cascaded Components 1 0 0 0 i , , i i S S N N e DUT N kT B GT B    i 0 e N N T kB GkB   00 0 / 1 1 / i i e added i SN T N F SN T N    2 , l j Le      ( 1) T LT e   0 1 ( 1) T F L T   1 0 11 1 2 2 2 ,, , , i e e N kTB N N G FT G F T     23 4 1 1 12 123 2 4 3 1 1 12 123 1 1 1 ee e e e TT T T T G GG GGG F F F F F G GG GGG                  2 2 21 21 a 2 2 11 | | (1 ) |1 | (1 | | ) s s out S G G S        21 21 0 1 1 G T F G T    21 1 ( 1) T T e G   12 21 22 11 1 s out s S S S S     

To conclude 2 ●●● ●●●● ●●●●● ●●●0 For Wilkinson power divider:G T.=(-1T=(2L-1)T ●●●●0 21 (21 ●●●● ●●●● ● §3.7 Dynamic Range F-2L@To Nonlinear device %=(a+2a,)+(a%+4a6)cos@w1 or 43<0 network coscos3 10 P(referred to output) ldB IdB compression point 3 -10 Slope =I 6263646 -30 -20-10 0 1020 (dBm) EXAMPLE 3.5,page 92. 2

To conclude - 2 §3.7 Dynamic Range For Wilkinson power divider: EXAMPLE 3.5, page 92. 2 21 1 2 G L  21 1 ( 1) (2 1) T T LT e G    0 F  2 @L T 0 Nonlinear device v or vi network   2 0 0 20 0 2 3 1 3 20 0 30 0 0 30 1 ( ) ( )cos 2 1 1 cos 2 cos 2 4 3 3 4 v a aV t a aV t t V V a a V           3 a  0

To conclude 3 ●●● ●●●● ●●●●● ●●●0 S 3.7 Intermodulation Distortion ●●●●● ●●●● 7 ●●●色 p(ou) DRY *SWR p(ou) DR,=g阶 P 30 P 201-02 202-01 ldB 个 P= (a%2 0 02-01 0102 -30 For Cascaded Components: 60 2仙0” 11 B-G -90 Noise level -120-9060-30 030 P:(dBm) To continue Chapter 4 Antennas and Propagation for Wireless System 3

1 2 1 0 1 ( ) 2 P aV   1 2 3 2 2 30 1 3( ) 2 4 P aV    V aa Ip  4 /3 1 3 To conclude - 3 §3.7 Intermodulation Distortion Chapter 4 Antennas and Propagation for Wireless System  2 1   1 2 2   1  2 2 1 2   0  For Cascaded Components: 1 3 ' " 23 3 1 1 P ( ) GP P    3 2 ( ) ( ) 3 1 3 0 0 * * out out l f P P DR DR N SNR N SNR         To continue

●●● Microwave and RF Design of 888 Wireless Systems Chapter 4 Antennas and Propagation for Wireless System Dr.Xian Qi Lin 4

Microwave and RF Design of Wireless Systems Chapter 4 Antennas and Propagation for Wireless System Dr. Xian Qi Lin 4

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●●● ●●●● ●●●● ●●●0 ●●●●0 ●●●0 ●●●● S 4.1 Antenna system parameters ●● 天线系统参数 §4.2 The Friis equation Friis方程 $4.3 Antenna noise temperature 天线噪声温度 §4.4 Propagation传播 4.5 Fading 衰落 6

§4.1 Antenna system parameters 天线系统参数 §4.2 The Friis equation Friis 方程 §4.3 Antenna noise temperature 天线噪声温度 §4.4 Propagation 传播 §4.5 Fading 衰落 6

●●● ●●●● ●●●●● ●●●0 S 4.1 Antenna system parameters ●●●●0 ●●●0 ●●●● ● Function of Antenna:converting a guided electromagnetic wave on a transmission line to a plane propagating in free space. 天线的功能：将传输线上的导行电磁波转化为自由空间传播的平面波 Parameter:radiation pattern(辐射方向图)，directivity(方向性)， gain(增益)，efficiency(效率)，polarization(极化) Spherical Plane wave wave Transmit Receive antenna antenna 7

§4.1 Antenna system parameters Function of Antenna: converting a guided electromagnetic wave on a transmission line to a plane propagating in free space. 天线的功能：将传输线上的导行电磁波转化为自由空间传播的平面波 Parameter: radiation pattern（辐射方向图）, directivity（方向性）, gain（增益）, efficiency（效率）, polarization（极化） Operation ： 7

●●● ●●●0 ●●●● ●0 1.Fields and Power Radiated by an Antenna ●●●● 天线的辐射场与功率 ●●0 ● ●2.Far-zone field distance远区场距离 ●3.Radiation Intensity辐射密度 ●4.Radiation Patterns辐射方向图 5.Directivity ●6.Radiation Efficiency辐射效率 ●7.Gain ●8.Aperture efficiency口径效率 ●9.Effective Area有效面积 ●l0.Antenna polarization天线极化 8

1.Fields and Power Radiated by an Antenna 天线的辐射场与功率 2. Far-zone field distance 远区场距离 3. Radiation Intensity 辐射密度 4. Radiation Patterns 辐射方向图 5. Directivity 6. Radiation Efficiency 辐射效率 7. Gain 8. Aperture efficiency 口径效率 9. Effective Area 有效面积 10. Antenna polarization 天线极化 8

●●● ●●●● 1.Fields and Power Radiated by an Antenna ●●●●● ●●●● ●●●●0 ●●●0 ●●● The radiated electric field of arbitrary antenna. 任意天线的辐射电场(at large distance,near-zone fields are negligible)在远距离，近区场可忽略时： .i where:0,are unit vectors,ko=2 Fo(0)F(0,)are Pattern functions 9

The radiated electric field of arbitrary antenna. 任意天线的辐射电场(at large distance, near-zone fields are negligible)在远距离，近区场可忽略时： 1.Fields and Power Radiated by an Antenna V m （ ）     0 ,, , , jk r e Er F F r                  where: are unit vectors, 0 2 k    ,     F  ,     F  ,     are Pattern functions 9

●●● ●●●● ●●●●● ●●●0 Conclusion: ●●●●0 ●●●● ●●● ● ● DPhase variation:e-/kor 相位变化 amplitude variation:1/ 幅度变化 3transverse electromagnetic (TEM)waves: polarized in either0or中directions.在p和OL的极化 The associated magnetic field:H EaH。= -E6 70 170 7=120-3779 The wave impedance of free space. 自由空间波阻抗 10

Conclusion: 0 jk r e ①  Phase variation: ②amplitude variation: 1 r ③transverse electromagnetic (TEM) waves: polarized in either  or  directions. 0   E H  0   E H  The associated magnetic field:  ＝ ＝ 120 377   The wave impedance of free space. 10 相位变化 幅度变化 在 和 上的极化   自由空间波阻抗