Bruker BLAH500 E, Operating & Service Manual

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Operating & Service Manual Version 002 BRUKER BIOSPIN 5 (51)
1
General
Information 1
Introduction 1.1
The BLAH500 E Amplifier 700-900MHz INR is a broadband linear pulse power
amplifier specifically designed for Nuclear Magnetic Resonance (NMR)
application for 16,4 to 21,1 Teslas Systems. It is commercialized under the
BRUKER BIOSPIN part number W1345505.
It is operated in AB linear class and provides 500W and more peak RF power over
the frequency range 650-900MHz on the H500 output for the Solid applications
and 50W and more peak RF power on the H50 output for the High Resolution
applications.
The amplifier is equipped with N-Channel RF LDMOSFETs transistors of the
latest generation. The unit can provide full power for any combination of pulse
width and duty cycle up to 100ms and 20% in High Resolution mode and 10% in
Solid mode.
Its built-in protection circuitry will allow lower power pulses for longer pulse widths
and duty-cycles, maintaining a 50W average power for the Solid application on
the H500 output and 10W average power for the High Resolution application on
the H50 output.
The electronic protection circuitry has been designed to protect against:
•
Excessive power output level (overdrive)
•
Excessive pulse repetition rate (over duty-cycle protection)
•
Excessive pulse duration (over pulse-width)
•
More than 50% reflected RF power (mismatch when VSWR
≥
6)
•
Thermal protection (overheat)
The amplifier is powered by an internal switched power supply assembly that
provides the +32VDC for the power amplifiers, in addition to all low level voltages
for the system.
The supply is self protected for overcurrent and overvoltage.
The entire unit is housed in a 19", 3U, 520mm rack cabinet.