Theory, Design and Tests on a Prototype Module of a Compact ...

5. COUPLING BETWEEN WAVEGUIDE AND BRIDGE COUPLER 43
[kΩ]
20
0
−20
−40
−60
−80
−100
2.9 3 3.1 3.2 3.3 3.4
f [GHz]
Figure 3.17. The Reactance of a 41 × 10 × 2 mm iris.
The dashed line interpolates the circles that are Superfish
points. The continuous line interpolates points from
Mafia.
In figure 3.18 are shown the dependencies of reflection coefficient
on the short-circuit length <strong>and</strong> on the capacitance C1 that is related
with the iris dimensions. These plots are important to underst<strong>and</strong> the
sensitivity of the iris design, <strong>and</strong> it is apparent that the matching is
very sensitive.
|Γ| dB
−20
−30
−40
−50
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−70
−80
−90
−100
0.94 0.96 0.98 1 1.02 1.04 1.06
d/d2
|Γ| dB
0
−10
−20
−30
−40
−50
−60
−70
0.5 1 1.5
C /C
1 10
Figure 3.18. Dependence of Γ on d2 (left). Dependence
of Γ on C1 (right).