Motorola GP280 Информация о сервисе - Страница 11
Просмотреть онлайн или скачать pdf Информация о сервисе для Двухстороннее радио Motorola GP280. Motorola GP280 32 страницы. Professional radio, power distribution and controller
Также для Motorola GP280: Руководство пользователя (46 страниц), Информация о сервисе (30 страниц), Руководство пользователя (46 страниц), Информация о сервисе (30 страниц)
Печатать страницу
1.0
Introduction
This Chapter provides a detailed theory of operation for the UHF circuits in the radio. For details of
the theory of operation and trouble shooting for the the associated Controller circuits refer to the
Controller Section of this manual.
2.0
UHF Transmitter
(Refer to Figure 2-1 and the UHF Transmitter schematic diagram)
The UHF transmitter consists of the following basic circuits:
1.
Power amplifier (PA).
2.
Antenna switch/harmonic filter.
3.
Antenna matching network.
4.
Power Control Integrated Circuit (PCIC).
From
VCO
2.1
Power Amplifier
The power amplifier (PA) consists of two principle devices:
1.
LDMOS PA driver IC, U101.
2.
LDMOS PA final stage, Q110.
The LDMOS driver IC 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 3dBm
(pin16). The current drain is typically 160mA while operating in the frequency range of 403-470MHz.
P CI C
Vcontrol
Power
Amplifier
PA
Driver
Figure 2-1 UHF Transmitter Block Diagram.
THEORY OF OPERATION
Vcontrol
Antenna Switch/
P A Final
S t a g e
Harmonic Filter
Chapter 2
Antenna
Matching
Network