R.V.R. Electronica PJ1000-LIGHT User Manual - Pj500C-Lcd & Pj1000-Light
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User Manual
Rev. 1.
0
- 15/12/06
PJ500C-LCD & PJ1000-LIGHT
8.4 PWR Input Measure Board (SLMPIPPJ1KC)
This board enables measurement of the following parameters:
• Input power measurement;
• Main heat sink temperature measurement by an LM 50 sensor mounted on the
board; it obtain the temperature through a fixing screw.
Both measurements are adequately processed and sent to the interface board
that controls the protection modules and relays the signals to the CPU board to
enable readings to be displayed.
8.5 Power amplifier
The RF power amplification section consists in several power modules (two on the
PJ500C-LCD
, three on the
PJ1000-LIGHT
) coupled through a Wilkinson splitter
and combiner using strip-line technology.
Each RF module of the
PJ500C-LCD
(code SL010RF1001) provides 300 W rated
power - which rise up to 350 W each for the
PJ1000-LIGHT
RF modules (code
SL010RF2001) - using a single active element built using MOS technology. RF
modules are fed by the switching power supply via the Bias board.
The splitter (Splitter Board code SLSITEX500L1 for
PJ500C-LCD
, or
SLSPLTEX1KL1 for
PJ1000-LIGHT
) splits the incoming power input signal equally
to all RF modules. The combiner (Combiner Board code SLCOTEX500L1 for
PJ500C-LCD
, or code SLCMBTEX1KL1 for
PJ1000-LIGHT
) 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.
8.6 LPF Board (SLLPFTEX1KL)
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 (figure 6.2). This provides a
convenient test point to check carrier characteristics,
but does not ensure an
accurate assessment of higher harmonics
.