Texas Instruments 2000 LF Series, Примечание к применению

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Lit Number: 11-06-21-068
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Equation [1] is the formula that determines at what frequency the antenna circuit
resonates and you can see how either the Capacitance (C) or the Inductance (L) can
be varied to arrive at the required frequency (ƒ). Some RF modules tune to resonance
by varying the capacitance, whilst the RFM-104B and the Remote Antenna Tuning
Boards both vary the inductance.
3.1.1 The RFM-104B Module
The RFM-104B (standard) RF module is shown in Figure 4
Figure 4. The RFM-104B RF Module
RFM-104B modules use a variable inductor to fine tune antennas. A representation of
the circuit is shown in Figure 5.
Figure 5. Inductance Fine-Tuning
Capacitance (C)
Variable
Inductance (L)
Antenna
Inductance (L)
Variable
Inductor