Single Stub Matching
Editor:張宏彬
Advisor:江簡富
(I) Analytic Approach
where n is an integer (positive or negative). The amplitude and phase of are
The parameter and can be expressed in terms of and as
(1)
(2)
Two possible solutions for b and ds are given in (1) and (2) respectively, where the integer value for n is chosen such that .
(II) Smith Chart Approach
(a) => point A
(b) Drawing constant SWR circle passing through A, go around the constant SWR circle by half a revolution to B which corresponds to
(c) The constant SWR is also the locus of
. Draw r = 1 circle and find C and F which correspond to two solutions of . The distance moved from B to C is the location of stub.
(d) Since the short circuit corresponds to a susceptance of infinity, we start at point D
(the outmost circle) to reach E which is the input admittance of the stub normalized with. The distance moved from D to E is the length of the stub.
(e) The second solution of can be obtained from (c), which is the distance moved
from B to F.
(f) The second solution of can be obtained from (d).where is the distance from D to G.
Parameter in DEMO:
,
=>
The general expressions for the line voltage and line current are
the waves satisfy the boundary condition given by:
(1) at =0 ,
(2) at =0 ,
(3) at =0 ,
(4) (5) at =0, =,=,
(6)
Form above , we can obtain voltage and current in which region as follows:
Region 1:
Region 2:
Region 3: