Rohde & Schwarz Inc TMU925 用户手册
Amplifier R&S PMU901
R&S
®
TMU9
84
System Manual 2600.5423.02 ─ 01
power detector PWR_OUT, the reflected power test point takes over power control. The
control amplifier supplies the control voltage V_REG as the output quantity and this volt-
age is fed to the amplitude regulator in the preamplifier.
control amplifier supplies the control voltage V_REG as the output quantity and this volt-
age is fed to the amplitude regulator in the preamplifier.
Additionally, the REFL_OUT signal is acquired at the reflected power test point. This
signal together with the PWR_OUT signal (forward power) is used for VSWR indication
at the amplifier output.
signal together with the PWR_OUT signal (forward power) is used for VSWR indication
at the amplifier output.
5.1.4.5
Self
‑Protection Mechanisms
The amplifier has a series of self
‑protection and monitoring mechanisms which protect it
against irreparable damage in the case of impermissible operating conditions and enable
transmission to continue for as long as possible. The following mechanisms are available.
transmission to continue for as long as possible. The following mechanisms are available.
● Power supply monitoring
● Input level monitoring
● Output power limitation
● Temperature monitoring incl. fan control
● Reflection monitoring
● Operating mode monitoring
● Input level monitoring
● Output power limitation
● Temperature monitoring incl. fan control
● Reflection monitoring
● Operating mode monitoring
Power supply unit monitoring
The power supply unit has the following self
‑protection mechanisms:
● Overtemperature shutdown for the duration of overtemperature
● Short
● Short
‑circuit current limitation
● Input voltage monitor (enables shutdown to limit the input current in the case of
undervoltage)
● Overvoltage limitation (on DC side)
If no standby power supply unit is installed, failure of the power supply unit (/
DC_OK = high) will mean failure of the amplifier. If a standby power supply unit is installed,
there will be no operational restrictions. The amplifier will however be completely deac-
tivated if both power supply units fail.
DC_OK = high) will mean failure of the amplifier. If a standby power supply unit is installed,
there will be no operational restrictions. The amplifier will however be completely deac-
tivated if both power supply units fail.
The overtemperature shutdown in the power supply is intended purely as a self
‑protection
mechanism only and is not indicated by the front LED as the DC voltage is switched off.
A temperature shutdown at the power supply is signaled only indirectly by the message /
DC_OK_x. The power supply unit has status LEDs for normal operation and fault indi-
cation. These LEDs are indirectly visible after removal of the front cover (and, where
applicable, the air filter).
A temperature shutdown at the power supply is signaled only indirectly by the message /
DC_OK_x. The power supply unit has status LEDs for normal operation and fault indi-
cation. These LEDs are indirectly visible after removal of the front cover (and, where
applicable, the air filter).
Input level monitoring
If the input level drops below a defined threshold (RF_IN_FAIL), power control is influ-
enced by the following measures:
enced by the following measures:
● The amplitude regulator for power control is switched to maximum attenuation
● The internal reference voltage for power control is suppressed
● The internal reference voltage for power control is suppressed
Design and Function R&S PMU901