Motorola HT Series

UHF Band 2 Theory of Operation: Transmitter 5-1
Chapter 5 UHF Band 2 Theory of Operation
5.1 Transmitter
Figure 5-1. Transmitter Block Diagram
5.1.1 General
(Refer to Figure 5-1)
The UHF transmitter contains five basic circuits:
• power amplifier
• antenna switch
• harmonic filter
• antenna matching network
• power control integrated circuit (PCIC)
5.1.2 Power Amplifier
The power amplifier consists of two devices:
• 9Z67 LDMOS driver IC (U101)
• PRF1507 LDMOS PA (Q110)
The 9Z67 LDMOS driver IC contains a 2 stage amplification with a supply voltage of 7.3 V.
This RF power amplifier is capable of supplying an output power of 0.3 W (pin 6 and 7) with an input
signal of 2 mW (3 dBm) (pin16). The current drain would typically be 160 mA while operating in the
frequency range of 450-527 MHz.
The PRF1507 LDMOS PA is capable of supplying an output power of 7 W with an input signal of
0.3 W. The current drain would typically be 1300 mA while operating in the frequency range of
450-527 MHz. The power output can be varied by changing the biasing voltage.
PCIC
Antenna
PA
Driver
Vcontrol
Vcontrol
From VCO
Jack
PA-Fin al
Sta ge
Antenna Switch/
Harmonic Filter/
Matching Network
PA_Final
Stage