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User Manual
Rev. 1.0 - 28/02/11
PJ1000C/1300C/2000LCD
ELETTRONICA
•
Power output disabled (set to OFF) by user in FNC operation menu;
•
Regulated power set to 0 Watt using the edit mode;
•
An alarm or fault condition has occurred.
7.3.3 Power Amplifier
The RF power amplification section consists in four power modules coupled through
a Wilkinson splitter and combiner using strip-line technology.
Each RF module provides 600 W rated power using a double active element built
using MOS technology (SD2932). RF modules are fed by the switching power
supply via the Bias board.
The splitter card splits the incoming power input signal equally to all RF modules.
The combiner card combines the power output signals available at module outputs
to obtain total amplifier power.
Splitter, amplifiers and combiner have been designed to sum amplifier output power
signals in phase, so as to keep unbalance and power dissipation to a minimum.
The whole RF section is mounted on a finned heat sink with fan cooling.
7.3.4 LPF Card
This board incorporates a low-pass filter to keep amplifier harmonics within
permissible limits as specified by international standards.
A directional coupler is provided at filter output to measure forward and reflected
RF output power; power readings are relayed to the Interface and Bias boards to
enable processing and display.
The LPF board incorporates an RF output (having a level about -60 dB lower than
output level) which is brought to a BNC connector. This provides a convenient test
point to check carrier characteristics,
but does not ensure accurate assessment
of higher harmonics
.
7.3.5 BIAS card
The main purpose of this board is to control and correct the bias voltage of
the RF amplification section MOSFETs.
It also provides a measure of the total current drawn by the RF modules and
incorporates a dedicated circuit for power supply fault reporting.
