User's Manual

30W FM AMPLIFIER MODULE MFF0025BR0

DESCRIPTION

The MFF0025B amplifier module is designed to amplify the FM modulated carriers in the 87-108MHz band,

and can provide an output of 30W CW. In order to obtain the desired gain, the amplifier is made up by two

gain stages: the pilot stage uses a BLF242 MOSFET, while the final stage uses a BLF245 MOSFET.

An input adaptation circuit allows the adaptation of the module to the various driving levels. The output power

regulation is made by controlling the power level of the input signal of the module. The final stage of the

module also has a control terminal allowing to disable the MOSFET immediately, if needed. The output of the

module is completed by a 9th order (4 cell) low-pass filter to attenuate the level of the harmonics of the signal,

and by two high-directivity directional couplers needed to sample part of the Forward and Reflected Power

in order to measure their levels. The final is provided with the needed circuits (SCH0371B Interface Board)

to read the output Forward and Reflected Power, the heatsink temperature and the voltage supplied.

TECHNICAL CHARACTERISTICS

Frequency Range 87 - 108MHz

Output Power 30W

Input Return Loss >25dB

Power Supply +27V

RF Input Impedance 50Ω

RF Output Impedance 50Ω

Bias Current BLF242 with Vdd = +27V: 220mA

Bias Current BLF245 with Vdd = +27V: 220mA

Gain 20dB

Efficiency 54%

MFF0025BR0 COMPONENT LIST

Part Name/Number Description Qty.

SCH0382BR0 30W FM AMPLIFIER BOARD 1

01400 BYPASSING CAPACITOR 1

01408 BYPASSING CAPACITOR 3

DET1304 DET1304R0 30W DISSIPATOR 1

DET1276 DET1276R0 AMPLIFIER REAR BAR 1

DET1277 DET1277R1 AMPLIFIER INPUT BAR 1

DET1239 DET1239R1 AMPLIFIER MODULE COVER 1

SCH0371BR0 INTERFACE BOARD 1

07907 TO220 INSULATOR 2

07910 TO220 INSULATOR 2

02515 SMB SCREW cod. R114313000 1

08502 RG 316 50Ω CABLE 0.15

02516 SMB CONNECTOR FOR PCB 1

02248 17x17 NF FLANGE CONNECTOR 1