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41 - ����������� - AC ��������
There you have it! The antenna is an LR circuit of 28j208Ω. So, the antenna is not
resonant since it has inductive reactance. The L-match converts the antenna
impedance to 51.75+j0.8Ω at the transmitter. The transmitter sees a very low, almost
perfect SWR. The transmitter then will develop full power into the load (the antenna
system). Where does all this power go? The L-match is made of reactive
components L and C. Reactance does not dissipate power. In practice, the L and C
of the L-match will have a very small amount of resistance, but none worth worrying
about. For practical purposes, all the power is being delivered to the antenna.
On receive the antenna is the source of power and the receiver is the load. The
source impedance of the receiver is 50j0Ω by design. Let's work out what the
antenna sees as a load when the antenna is acting as a source.
Figure 41-28
Looking from the antenna's perspective towards the load, we need to first calculate
the load (the receiver) source impedance of 50j0Ω in parallel with the inductor of
0+j55.21Ω
PREVIEW
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