Master1 Communication Micro-ondes

Adaptation à l’aide d’un Stub

Z L

d/λ

s/λPar :

D. Sayad

M1 Communication : Microondes D. Sayad

o

r = 1

Abaque de Smith

M1 Communication : Microondes D. Sayad

Exemple: Réaliser l’adaptation d’une charge : zL=2 – j 1.5

à l’aide d’un stub court-circuité.

d/λ= ?

s/λ= ? Z L

d/λ

s/λ

r = 2

x = -1.5

M1 Communication : Microondes D. Sayad

o

r = 1

r = 2

Cercle r = 2

Placement du point (2,-1.5)

r = 2

x = -1.5

M1 Communication : Microondes D. Sayad

o

r = 1

r = 2

x = -1.5 Cercle r = 2

Cercle x = -1.5

r = 2

x = -1.5

Placement du point (2,-1.5)

M1 Communication : Microondes D. Sayad

o

r = 1

r = 2

x = -1.5

r = 2

x = -1.5

Placement du point (2,-1.5)

M1 Communication : Microondes D. Sayad

o

r = 1

r = 2

x = -1.5

z = 2 – j 1.5

r = 2

x = -1.5

Placement du point (2,-1.5)

A

A: z = 2 – j 1.5

M1 Communication : Microondes D. Sayad

o

r = 1

r = 2

x = -1.5

Déduction du coefficient de réflexion | |

Φ = -29.74°

= 0.54 (-29.74°) = 0.54 (-29.74°)

o

r = 1

r = 2

x = -1.5

M1 Communication : Microondes D. Sayad

Tracé du cercle de rayon | |

| |= 0.54

M1 Communication : Microondes D. Sayad

o

r = 1

r = 2

x = -1.5

Tracé du cercle de rayon | |

| |= 0.54

M1 Communication : Microondes D. Sayad

o

r = 1

r = 2

x = -1.5

g = 0.32

Détermination de l’admittance de charge yL

M1 Communication : Microondes D. Sayad

o

r = 1

r = 2

x = -1.5

g = 0.32

x = 0.24

yL = 0.32 + j 0.24

b = 0.24

B

B: yL = 0.32 + j 0.24

M1 Communication : Microondes D. Sayad

o

r = 1

y1 = 1 + j 1.27

•Détermination du point d’intersection avec le cercle unité y = 1.

•Détermination de d/λ.

d/λ = 0.129

M1

M1: y1 = 1 + j 1.27

M1 Communication : Microondes D. Sayad

o

r = 1

y1 = 1 + j 1.27

y = 0 – j 1.27

Point de CC en admittance

•Détermination de s/λ.

S=0.106λ

Cas d’un Stub court-circuité

C

C: y = 0 – j 1.27

M1 Communication Micro-ondes

D. Sayad

Adaptation à l’aide d’un Stub

Z L

d/λ

s/λ