Motorola GP140 Series 서비스 정보 - 페이지 11
{카테고리_이름} Motorola GP140 Series에 대한 서비스 정보을 온라인으로 검색하거나 PDF를 다운로드하세요. Motorola GP140 Series 30 페이지. Professional radio, power distribution and controller
Motorola GP140 Series에 대해서도 마찬가지입니다: 사용자 설명서 (20 페이지), 서비스 정보 (32 페이지), 기본 서비스 매뉴얼 (46 페이지), 서비스 정보 (30 페이지)
페이지 인쇄
1.0
Introduction
This Chapter provides a detailed theory of operation for the VHF 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
VHF Transmitter
(Refer to Figure 2-1 and the VHF Transmitter schematic diagram)
The VHF 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 consists of two devices:
1. LDMOS driver IC (U3501)
2. LDMOS PA (Q3501)
The LDMOS driver IC contains two stages of 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 is typically around 130mA while operating in the
frequency range of 136-174MHz.
PCIC
Vcontrol
Power
Amplifier
PA
Driver
Figure 2-1 VHF Transmitter Block Diagram.
THEORY OF OPERATION
Vcontrol
PA Final
Antenna Switch/
Stage
Harmonic Filter
Chapter 2
Antenna
Matching
Network