User's Manual

30 kW S-BAND/U ANTENNA GROUP
FUNCTIONAL DESCRIPTION
3.11 Rev. C
3 .3 .3 .4 Azim ut h and Hea ding Line Signa l Circuit
Genera t or
The antenna Unit must constantly forward its Azimuth position and Heading
Line to the Display unit. The function of this circuit (Chapter 9, Figure 9.1.14) is
to process the incoming signal AZIN and HLIN and forward to the micro
controller the signal AZ and HL for blanking function.
The output signal AZOUT and HLOUT are used on the Display Unit.
3 .3 .3 .5 Per form ance Monit or Funct ion
The Performance Monitor functions (Chapter 9, Figure 9.1.15) are to monitor
Transceiver performance in order to allow the Noise Ring presentation on PPI.
In the related circuit there is a diode, operating as a rivelator when the RF is
received or as noise generator when the signal NE is available. When the diode
is operating as rivelator he is synchronised with the peak power of the signal
and the rivelator circuit can rivelate the power present at the diode starting,
(GSTC triggers) 1/16 in advance of normal trigger and finishing when MCUR
signal is present.
The TRPM trigger is an incoming trigger in the PM circuit and his function is to
allow the generation of the NE, Noise Enabling, signal. At the same circuit will
arrive, generated by the PWLEVEL, the SN, Source Noise signal as well. The
delay between TRPM and NE signal is a function of SN voltage value; therefore
the Noise Ring will bed function of the distance.
When the command PMON, Performance Monitor ON, is available, in the PM
circuit there is the 120 Voltage as well, forwarded by POWER MOS Board and
supplying a neon lamp in Antenna. A neon lamp, placed in front of the Antenna,
on a monitor arm protruding from the antenna pedestal, is excited at each
antenna scan by the radiated RF pulse energy, when the radiation beam
crosses over. The result is that when the Performance Monitor is switched on
and the neon lamp is radiated by the Magnetron RF, the RF energy causes a
current variation on neon lamp and a signal is generated. A detector circuit
provides to pick up this signal and to generate the signal NO, Noise Open,
opening the Noise Ring.
The Neon Lamp function is to verify as well the Magnetron functioning and to
provide a general idea on the output power on air.
According to the VDLEVEL signal, the proper circuit generates the NT (Noise
Thickness) signal; in case of VD variation also a thickness variation occurs.
3 .3 .4 Solid St a t e R.F. H ead
The RF Head (Chapter 9, Figure 9.1.16) is composed of a solid state
MAGNETRON stage connected to a CIRCULATOR and ending with a flange to
be connected to a RF Coaxial Cable in order to transfer the RF PULSE to the