R.V.R. Elettronica HC4, User Manual

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HC4
7 / 34 User Manual Rev. 1.0L - 01/04/02
4. General Desciption
The HC4, produced by R.V.R. Elettronica, is a hybrid coupler at 4 way realized in
"Strip-Lines" technology. Its function is to split the RF signal coming from a RF
exciter, adjusting the relative phases, to pass them through four external RF power
amplifiers and then to combine the output of the amplifiers into a single RF amplified
signal to be forwarded to the antenna output.
The HC4 is produced in the version for four transmitters of 1 kW max output power
everyone (total 4 kW).
Exciter
HC4
RF
Amplifier #4
Spl
Σ
RF
Amplifier #2
RF
Amplifier #1
RF
Amplifier #3
The nominal working principle of a FM transmitter based on a hybrid coupler scheme
like HC4, foresees that the used amplifiers shall produce the same RF power that
will be added with the same phase. Possible differences in the power level or
phase of the amplifiers generate the so-called unbalancement power that is in part
dissipated inside the coupler. The HC4 guarantees the overall working of the
transmitter even if one of the amplifiers is completely off-service. In such case,
approximately 2,4 kW of the power generated by the surviving amplifier is routed
to the antenna anyway; the other part of the delivered power (that is unbalancement
power) is dissipated inside the combiner.
The HC4 is controlled by a microcontroller system, that includes a LCD display
and a series of keys for the interaction with the user, that realizes the following
functions:
• Measurement and visualization of the coupler’s working parameters
• Activation and deactivation of the power output of the system
• Protection of the coupler with respect to potentially dangerous situations like
exceeding emitted or unbalancement power, overdrive or overtemperature
• Detection of user-settable attention thresholds (e.g. output power being below
a certain value), that are made externally available as digital states on the
"telemetry" connector
• Communications with external devices