射频 李缉熙RF培训课件 RF课件 Lecture03_Impednce mtching for nrrow nd lock

1、Lecture 3,Richard Li, 2009,1,Lecture 3,Richard Li, 2009,2,1. Introduction,Lecture 3,Richard Li, 2009,3,2. Impedance Matching by Means of Return Loss Adjustment,Return Loss Circles on Smith Chart,Note 1: Power reflection coefficient, , and return loss, RL ( S11 or S22), is bold-marked with values alo

2、ng the vertical axis, V, such as, =1, RL=0 dB, =0.79, RL=-1 dB, =0.63, RL=-2 dB, and so on. Note 2: Normalized resistance, r, is bold-marked with values around the biggest circle, Such as, 0, 0.1, 0.2, 0.5, 1, 1.5, 2, 3, 5, 10, , -10, -5, -3, -2, -1.5, -1, -0.5, -0.2, -0.1. Note 3: Normalized reacta

3、nce, x, is bold-marked with values along the horizontal axis U, Such as, 0, 0.2, 0.5, 1, 2, 5, .,Figure 2 Constant return loss S11, dB or S22, dB circles on Smith Chart,V,U,E,W,N,O,S,10,5,3,2,1.5,1,0.5,0.2,-0.2,-0.5,-5,-3,-2,-1.5,-1,-10,0,=0.79, RL=-1 dB,=0.63, RL=-2 dB,=0.50, RL=-3 dB,=0.40, RL=-4

4、dB,=0.32, RL=-5 dB,=0.25, RL=-6 dB,=0.20, RL=-7 dB,=0.10, RL=-10 dB,=0.03, RL=-15 dB,=0.01, RL=-20 dB,=1.00, RL= 0 dB,=0.00, RL= -,Lecture 3,Richard Li, 2009,4,Relationship between Return Loss and Impedance Matching,RL = S11 or S22 = - 15 dB,r = 0.6980 and 1.4326,R = 34.9020 and 71.6291.,Table 1 Var

5、iation of return loss RL along with U axis (V=0) Resistance, ReferenceNormalizedPower Ref. Return loss,RL R,resistanceresistance, rcoefficient,S11 or S22 Ro, r=R/Ro = 2 dB 2.8750500.05750.79-1 5.7313500.11460.63-2 8.5500500.17100.50-3 11.3136500.22630.40-4 14.0066500.28010.32-5 16.6140500.33230.25-6

6、 19.1236500.38250.20-7 21.5252500.43050.16-8 23.8110500.47620.13-9 25.9747500.51950.10-10 29.9240500.59860.06-12 34.9020500.69800.03-15 40.9091500.81820.01-20 44.6760500.89350.00-25 46.9347500.93870.00-30 48.2528500.96510.00-35 49.0099500.98020.00-40 49.4408500.98880.00-45 49.6848500.99370.00-50 50.

7、0000501.00000.00(-Infinite) 50.3172501.00630.00-50 50.5655501.01130.00-45 51.0101501.02020.00-40 51.8105501.03620.00-35 53.2656501.06530.00-30 55.9585501.11920.00-25 61.1111501.22220.01-20 71.6291501.43260.03-15 83.5450501.67090.06-12 96.2475501.92500.10-10 104.9942502.09990.13-9 116.1431502.32290.1

8、6-8 130.7280502.61460.20-7 150.4750503.00950.25-6 178.4900503.56980.32-5 220.9700504.41940.40-4 292.4050505.84810.50-3 436.2200508.72440.63-2 869.55005017.39100.79-1,RL = S11 or S22 = - 10 dB,r = 0.5195 and 1.9250,R = 25.9747 and 96.2475 ,RL = S11 or S22 - 10 dB,Impedance matching state is acceptabl

9、e,Demarcation circle of RL,Impedance matching state is unacceptable,RL = S11 or S22 - 10 dB,Lecture 3,Richard Li, 2009,5,Implementation of an Impedance Matching Network,Lecture 3,Richard Li, 2009,6,Lecture 3,Richard Li, 2009,7,3. Impedance matching Network built by One Part,o One part Inserted into

10、Impedance matching Network in series,Lecture 3,Richard Li, 2009,8,Lecture 3,Richard Li, 2009,9,Lecture 3,Richard Li, 2009,10,The addition of an inductor in series, LS, results the original impedance P moving clockwise along the r = constant impedance circle. The moved arc length depends on the value

11、 of inductor; The addition of a capacitor in series, CS, results the original impedance P moving counter-clockwise along the r = constant impedance circle. The moved arc length depends on the value of capacitor; The addition of an inductor in parallel, LP, results the original impedance P moving cou

12、nter-clockwise along the g = constant admittance circle. The moved arc length depends on the value of inductor; The addition of a capacitor in parallel, CP, results the original impedance P moving clockwise along the g = constant admittance circle. The moved arc length depends on the value of capaci

13、tor; The addition of a resistor in series, RS, results the original impedance P moving along the x = constant arc to a higher resistance circle. The moved distance depends on the value of resistor; The addition of a resistor in parallel, RP, results the original impedance P moving along the x = cons

14、tant arc to a lower resistance circle. The moved distance depends on the value of resistor.,Figure 9 shows the moving direction of the impedance at point P if one passive part, L, or C, or R, is added. The variation of impedance on Smith Chart would obey the following thumb of rules if one inductor,

15、 or one capacitor, or one resistor is added to the original impedance P of the port:,Lecture 3,Richard Li, 2009,11,2. Impedance Matching network built by Two Parts,Regions in the Smith Chart,Table 2 Range of impedance in 4 regions on a Smith Chart Region 1 Region 2 Region 3 Region 4 Low resistance o

16、r High resistance or Low resistance and Low resistance and high conductance low conductance low conductance low conductance r 1, r 0, x 1, g 0 .,Lecture 3,Richard Li, 2009,12,Lecture 3,Richard Li, 2009,13,E,V,S,N,O,U,W,Figure 11(d) Two ways to pull the original impedance P4 in region 4 to the center

17、 of Smith Chart ,O, by addition of two passive parts,Lecture 3,Richard Li, 2009,14,There are two ways to pull P1 to the center of Smith Chart, 50 : 1) In Figure 10.11(a) P1 is pulled to A by the addition of a capacitor CS in series first, and then from A to O by the addition of an inductor LP in par

18、allel. 2) In Figure 10.11(a) P1 is pulled to B by the addition of an inductor LS in series first, and then to pull B to O by the addition of a capacitor CP in parallel. There are two ways to pull P2 to the center of Smith Chart, 50 : 1) In Figure 10.11(b) P2 is pulled to C by the addition of an indu

19、ctor LP in parallel first, and then from C to O by the addition of a capacitor CS in series. 2) In Figure 10.10(b) P2 is pulled to D by the addition of a capacitor CP in parallel first, and then to pull D to O by the addition of an inductor LS in series. There are two ways to pull P3 to the center o

20、f Smith Chart, 50 : 1) In Figure 10.11(c) P3 is pulled to B by the addition of a capacitor CS in series first, and then from B to O by the addition of a capacitor CP in parallel. 2) In Figure 10.11(c) P3 is pulled to C by the addition of a capacitor CP in parallel first, and then to pull C to O by t

21、he addition of a capacitor CS in series. There are two ways to pull P4 to the center of Smith Chart, 50 : 1) In Figure 11(d) P4 is pulled to D by the addition of an inductor LP in parallel first, and then from D to O by the addition of an inductor LS in series. 2) In Figure 11(d) P4 is pulled to A b

22、y the addition of an inductor LS in series first, and then to pull A to O by the addition of an inductor LP in parallel.,Lecture 3,Richard Li, 2009,15,There are three common rules or features can be summarized from the description above, they are: The first part in a two parts impedance matching net

23、work is to pull the original impedance to either one of the circles g=1 or r=1. Then, The second part in a two parts impedance matching network is to pull the impedance on the circle either g=1 or r=1, after it is pulled by first part, to the standard reference impedance, 50 . 3) One of two matching

24、 parts is in series and another one is in parallel. However, the designer can select the first part in series or in parallel, because as described above, for all possible original impedances there are two ways to be pulled to the center of Smith Chart. The first part in one way is in series while in

25、 another way is in parallel, and vice versa.,Lecture 3,Richard Li, 2009,16,Region 1 Low resistance & high conductance: r1, b=- to +,Lecture 3,Richard Li, 2009,17,Region 2 High impedance & low conductance: r1, x= - to +, g1, b|0.5|,Lecture 3,Richard Li, 2009,18,Region 3 Low resistance & low conductan

26、ce: r0, g1, b0,Lecture 3,Richard Li, 2009,19,Region 4 Low resistance & low conductance: r0,Lecture 3,Richard Li, 2009,20,For P1 and P2,Region 1: For P1 : Rm Zo = 50 ohm In series first and in parallel second,First matching part, XS, in series, is to get g = 1. If g = 1, then,When g = 1, then y(g,b)

27、can be pulled to Zo by second part, xp,General formula for impedance and admittance,For P3 and P4, the impedance after adding of 1st part,XP, in parallel,Region 2: For P2 : Rm Zo = 50 ohm In parallel first and in series second,First matching part, XP, in parallel, is to get r = 1, If R = Zo, or r =

28、1, then,When R = Zo, or r = 1, then z(r,x) can be pulled to Zo by second part, XS,General formula for impedance and admittance,+ for Ls - for Cs,+ for Lp - for Cp,+ for Ls - for Cs,+ for Cp - for Lp,Lecture 3,Richard Li, 2009,21,For P1 and P2,Region 3 & 4 For P3 : Rm Zo = 50 ohm In series first and

29、in parallel second,First matching part, XS, in series, is to get g = 1. If g = 1, then,When g = 1, then y(g,b) can be pulled to Zo by second part, xp,General formula for impedance and admittance,For P3 and P4, the impedance after adding of 1st part,XP, in parallel,Region 3 & 4 For P4 : Rm Zo = 50 oh

30、m In parallel first and in series second,First matching part, XP, in parallel, is to get r = 1, If R = Zo, or r = 1, then,When R = Zo, or r = 1, then z(r,x) can be pulled to Zo by second part, XS,General formula for impedance and admittance,+ for region 3, Cs - for region 4, Ls,+ for region 3, Cp -

31、for region 4, Lp,+ for region 4, Lp - for region 3, Cp,+ for region 4, Ls - for region 3, Cs,Lecture 3,Richard Li, 2009,22,* Upward impedance transformer : From pure resistor to pure resistor,* Downward impedance transformer :,V,U,E,W,S,N,O,A,Rm,Ro,B,Figure 12 Upward and downward impedance transform

32、er,Lecture 3,Richard Li, 2009,23,o Key points in the case of two parts added on Smith Chart,* The 1st component is to bring the impedance to the circle with reference resistance or reference admittance.,* Matching network in region 1 is an upward impedance transformer. - It can transfer the impedanc

33、e from low to high (50 ohm here). - Usually it is the case of power amplifier design.,* Matching network in region 2 is a downward impedance transformer. - It can transfer the impedance from high to low (50 ohm here). - Usually it is the case of LNA, mixer etc.with CMOS processing.,* Matching networ

34、k in region 3 and 4 is an simple matching unit with only one type of parts. - In region 3 it can be matched only by capacitors. One is in series and another one in parallel. It doesnt matter to the order of these two capacitors. - In region 4 it can be matched only by inductors. One is in series and

35、 another one in parallel. It doesnt matter to the order of these two capacitors.,* The 2nd component is to bring the impedance to the center of Smith Chart, that is, to the point of the reference resistance and zero reactance,Lecture 3,Richard Li, 2009,24,o Selection of Topology,Consideration of the

36、 availability of topology,Table 3 8 possible topologies of an impedance matching network containing two passive parts 1. CP - LS 2. LS - CP 3. CS - LP 4. LP - CS 5. CP - CS 6. CS - CP 7. LP - LS 8. LS - LP Note 1: The first part is connected to the original impedance to be matched and the second par

37、t is connected to the standard reference impedance, 50 Note 2: The subscript “P” stands for “in parallel” and the subscript “S” stands for “in series”.,Lecture 3,Richard Li, 2009,25,Table 4 Applied and prohibited regions of an impedance matching network with specific topology Zm is located inZm is l

38、ocated in TopologyApplied regionProhibited region 1.CP - LSRegions 2,3Regions 1,4 2.LS - CPRegions 1,4Regions 2,3 3.CS - LPRegions 1,3Regions 2,4 4.LP - CSRegions 2,4Regions 1,3 5.CP - CSRegion 3Regions 1,2,4 6.CS - CPRegion 3Regions 1,2,4 7.LP - LSRegion 4Regions 1,2,3 8.LS - LPRegion 4Regions 1,2,

39、3 Note 1: Zm=Original impedance to be matched. Note 2: In the column of “topology” the first part is connected to the original impedance to be matched and the second part is connected to the standard reference impedance, 50 . Note 3: The subscript “P” stands for “in parallel” and the subscript “S” s

40、tands for “in series”.,Candidates : LS CP , LP CS , LP LS , LS LP .,Lecture 3,Richard Li, 2009,26,2) Consideration of cost,Candidates : LS CP , LP CS ,Lecture 3,Richard Li, 2009,27,3) Consideration of DC Blocking, DC feeding, and DC short-circuited,Candidate : LP CS .,Lecture 3,Richard Li, 2009,28,F

41、igure 15 Infinite moving paths of “” and “T” type impedance matching network,o Impedance Matching Network Built by Three parts,* Limitation by two parts scheme Impedance on Smith Chart can be moved to anywhere by three parts * More flexible The values of three parts are adjustable,(a) type of impeda

42、nce matching network with topology CP1, LS, and CP2 .,Lecture 3,Richard Li, 2009,29,Table 5 Possible topologies of 3 parts impedance matching network “” type “T” type 1.CP1 - CS - CP2,CS1 - CP - CS2, 2.LP1 CS - CP2,LS1 - CP - CS2, 3.CP1 - LS - CP2,CS1 - LP - CS2, 4.LP1 - LS - CP2,LS1 - LP - CS2, 5.C

43、P1 - CS - LP2,CS1 - CP - LS2, 6.LP1 - CS - LP2,LS1 - CP - LS2, 7.CP1 - LS - LP2,CS1 - LP - LS2, 8. LP1 - LS - LP2,LS1 - LP - LS2 . Note 1: In the “topology” list, the first part is connected to the original impedance to be matched, and the second part is connected to the standard reference impedance

44、, 50 . Note 2: The subscript “P” stands for “in parallel” and the subscript “S” stands for “in series”.,* “” type and “T” types,Lecture 3,Richard Li, 2009,30,o matching network :,Lecture 3,Richard Li, 2009,31,Lecture 3,Richard Li, 2009,32,o T matching network,Lecture 3,Richard Li, 2009,33,Lecture 3,

45、Richard Li, 2009,34,o Recommended Topologies,Consideration of cost,Candidates : “” type “T” type 1.CP1 - CS - CP2,CS1 - CP - CS2, 2.LP1 CS - CP2,LS1 - CP - CS2, 3.CP1 - LS - CP2,CS1 - LP - CS2, 5.CP1 - CS - LP2,CS1 - CP - LS2,Table 8 Applied and prohibited regions of an impedance matching network wi

46、th specific topology (From there the impedance Zm is going to be matched to 50 .) TopolgyApplied regionsProhibited regions “” type 1.CP1 - CS - CP2Region 3Regions 1, 2, 4 2.LP1 - CS - CP2,Regions 2, 3, 4Region 1 3.CP1 - LS - CP2,Regions 1, 2, 3, 4None 5.CP1 - CS - LP2,Regions 1, 3Regions 2,4 “T” typ

47、e 1. CS1 - CP - CS2,Region 3Regions 1, 2, 4 2.LS1 - CP - CS2,Regions 1, 3, 4Region 2 3.CS1 - LP - CS2,Regions 1, 2, 3, 4None 5.CS1 - CP - LS2,Regions 2, 3Regions 1, 4 Note 1: In the “topology” list, the first part is connected to the original impedance to be matched, and the second part is connected

48、 to the standard reference impedance, 50 . Note 2: The subscript “P” stands for “in parallel” and the subscript “S” stands for “in series”.,2) Consideration of the availability of topology.,Lecture 3,Richard Li, 2009,35,3) Consideration of DC blocking, DC feeding, and DC short-circuited.,LP1,50 ,Fig

49、ure 18 LP1 -CS -CP2 topology of impedance matching network available for input and output of a device.,CS,C,B,E,DC Bias,Input impedance matching network,50 ,CS,LP1,Output impedance matching network,Vcc,No problem for: DC blocking DC short-circuited DC feeding,CP2,CP2,Lecture 3,Richard Li, 2009,36,Li

50、nfinite,Linfinite,CP2,50 ,Vcc,Figure 19 CP1-LS-CP2 topology of impedance matching network problematical for input and output of a device.,LS,C,B,E,DC Bias,Input impedance matching network,50 ,LS,CP1,Output impedance matching network,CP1,CP2,Problems: Two DC blocking capacitors must be provided Two L

51、infinite parts must be provided,Lecture 3,Richard Li, 2009,37,Linfinite,Figure 20 CP1-CS-LP2 topology of impedance matching network problematical for input and output of a device.,Linfinite,LP2,50 ,CS,C,B,E,DC Bias,Input impedance matching network,50 ,CS,LP2,Output impedance matching network,Vcc,CP1

52、,CP1,Problem: Two Linfinite parts must be provided,Lecture 3,Richard Li, 2009,38,Linfinite,Linfinite,LS1,50 ,Figure 21 LS1-CP-CS2 topology of impedance matching network problematical for input and output of a device. .,CS2,C,B,E,DC Bias,Input impedance matching network,50 ,CS2,LS1,Output impedance m

53、atching network,Vcc,Problem: Two Linfinite parts must be provided,CP,CP,Lecture 3,Richard Li, 2009,39,Linfinite,Linfinite,CS2,50 ,Vcc,Figure 22 CS1-LP-CS2 topology of impedance matching network problematical for input and output of a device.,LP,C,B,E,DC Bias,Input impedance matching network,50 ,CS1,Output impedance matching network,CS1,C2,LP,Problem: Two Linfinite parts must be provided,Lecture 3,Richard Li, 2009,40,Figu