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6B-4
Transmitter
3.0
Transmitter
3.1
General
(Refer to Figure 6-1)
The VHF transmitter contains five basic circuits:
1.
power amplifier
2.
antenna switch
3.
harmonic filter
4.
antenna matching network
5.
power control integrated circuit (PCIC).
3.1.1 Power Amplifier
The power amplifier consists of two devices:
1.
9Z67 LDMOS driver IC (U3501) and
2.
PRF1507 LDMOS PA (Q3501).
The 9Z67 LDMOS driver IC contains a 2 stage amplification with a supply voltage of 7.3V.
This RF power amplifier is capable of supplying an output power of 0.3W (pin 6 and 7) with an input
signal of 2mW (3dBm) (pin16). The current drain would typically be 130mA while operating in the
frequency range of 136-174MHz.
The PRF1507 LDMOS PA is capable of supplying an output power of 7W with an input signal of 0.3W.
The current drain would typically be 1800mA while operating in the frequency range of 136-174MHz.
The power output can be varied by changing the biasing voltage.
Figure 6-1: Transmitter Block Diagram
P C I C
Antenna
P A
Driver
Vcontrol
Vcontrol
From VCO
Jack
PA-Final
Stage
Antenna Switch/
Harmonic Filter/
Matching Network
Summary of Contents for GP328
Page 1: ...GP328 GP338 Portable Radios Detailed Service Manual 6804110J64 F June 2002 ...
Page 4: ......
Page 8: ...iv ...
Page 16: ...xii ...
Page 20: ...2 2 Recommended Test Tools ...
Page 22: ...3 2 Error Codes ...
Page 60: ...5 4 Parts List Keypad Basic ...
Page 76: ...6A 14 Notes For All Schematics and Circuit Boards ...
Page 120: ...6B 14 Notes For All Schematics and Circuit Boards ...
Page 230: ...6D 36 Circuit Board Schematic Diagrams and Parts List ...
Page 248: ...6E 12 Notes For All Schematics and Circuit Boards ...
Page 270: ...7 4 Parts List for Universal Connector Flex ...