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Theory of Operation
: Low Band Transmitter
2-27
2.16 Low Band Transmitter
The low band transmitter consists of the following basic circuits as shown in
• Power amplifier (PA).
• Antenna switch/harmonic filter.
• Antenna matching network.
• Power control integrated circuit (PCIC).
Figure 2-18. Low Band Transmitter Block Diagram
2.16.1 Power Amplifier (PA)
The PA consists of two LDMOS devices:
• PA driver, U101.
• PA final stage, Q100.
The LDMOS driver (U101) provides 2-stage amplification using a supply voltage of 7.3V. The
amplifier is capable of supplying an output power of 0.3W (pins 6 and 7) with an input signal of 2mW
at (pin16). The current drain is typically 120mA while operating in the frequency range of
29.7 –50 MHz. The power output of this stage is varied by the power control loop which controls the
voltage on pin 1.
The LDMOS PA is capable of supplying an output power of 8W with an input signal of 0.3W. The
current drain is typically 2000 mA while operating in the frequency range of 29.7– 50 MHz. The final
stage gate is bias by a voltage from PCIC, pin 24. This voltage is the output of a programmable DAC
inside the PCIC and the output is adjustable with the radio tuner.
PCIC
PA
Driver
Antenna Switch/
Harmonic Filter
PA Final
Stage
Vcontrol
SPI Bus
Gate Bias
Antenna Switch Bias
Antenna
Matching
Network
From VCO
Power Amplifier (PA)
Содержание PR860
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Страница 5: ...iv Notes ...
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Страница 13: ...Notes xii List of Figures ...
Страница 17: ...1 4 Introduction Radio Model Information Notes ...
Страница 51: ...2 34 Theory of Operation Voltage Control Oscillators VCO Notes ...
Страница 81: ...4 4 Schematic Diagrams Overlays and Parts Lists Flex Layout Notes ...
Страница 193: ...4 116 Schematic Diagrams Overlays and Parts Lists Low Band Section Notes ...
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