4 kW FM Transmitter      
 
 

FM transmitter with output power of 4 kW is a complex system which consists of the following units:

  • Digital FM exciter (DFME) with output power of 30 W;

  • Phase-amplitude FM corrector;

  • Four amplifiers with output power of 1 kW;

  • Two Wilkinson type combiners, that combine output signals of two amplifiers;

  • Output 3 dB coupler, that combines output of Wilkinson combiners;

  • Dummy load, with heat sink and forced air cooling;

  • Output low-pass filter;

  • System for forced air cooling for the whole system;

  • Power distribution, that monitors three-phase power supply and forwards it to the system units so that the power consumption per phase is unified and

  • Central controller, that monitor the whole system operation.

The exciter and the amplifier with output power of 1 kW can be used independently, while the other units serve certain system functions.

 

The exciter, as well as the amplifiers, have completely digitized control of all functions (emitted and reflected power measurement, synthesis state, monitornig of the power supply voltages, etc.). The central controller monitors signal at the Wilkinson combiner output (at  2 kW level), output sognal (at 4 kW level), output 3 dB coupler debalance, dummy load temperature, environment temperature and airflow in the system for forced air cooling. The control in all devices is based upon microprocessors that enables serial communincation throuh RS232 port woht other system parts or with a PC computer.

This device, through the controller, has the remote monitoring and control possibility.

TECHNICAL CHARACTERISTICS


Frequency range
Output RF power
Power amplification
Nominal driver power
Amplifying element
Input / output impedance
Input connector
Output connector
Maximum permitted VSWR




87.5–108 MHz
> 4 k W
> 29 dB
5 W
MOS-FET
50 W
BNC
15/8"
< 1.8


BLOCK DIAGRAM
  Copyright 2002 IMTEL Microwaves home | products | tv products | fm products | modules | custom design | about us | contact
    Axis studio & SMDesign