Power Amplifier Section 600W FM Designed primarily for FM application, with a reliable Power Ldmos device. This amplifier is suitable for any CW or pulsed application. Output power detector and temperature detector available as option. 87.5-108 Mhz Pout : 600 W typ Gain : 23dB typ 50 Ohm in/out impedance Class B Devices : MRF6VP2600H or equivalent Supply : 30-48 Vdc 43V nominal Dimensions : (LxWxH):140x68x21mm 5,55 x2,67 x0,82 Absolute maximum ratings Parameter Value Symbol Voltage supply 52Vdc Vs Supply current 20 Adc Is Operating Temperature range 0 +70 C Note1 Storage Temperature range -30 +90 C Load Mismatch (full power, all phase angle) 2:1 Note2 Electrical Specifications Parameter Min. Typ. Max. Units. Note Frequency range 87.5 108 Mhz Power gain (saturated) 21 24 db Note3 Power Output 550 600 650 W Power Input 2 5 8 W Note4 Efficiency 74 80 % Note5 Supply voltage 30 48 V Power gain variation +/-0.5 +/-1 db F2 Second Harmonic -28-24 db F3 Third Harmonic -28-24 db
Typical performances Wideband low level response
90 @ Pout 600W ALC Control Pin: 4W, Ids=250mA 80 Vcc (V) - Efficiency (%) 70 60 50 40 30 87,5 92 98 102 108 Frequency (MHz) Vcc @ Pout 600W Efficiency @ Pout 600W 900 Pin: 4W, Ids=250mA 120 800 115 700 110 Pout (W) 600 500 400 300 105 100 95 90 85 Efficiency (%) 200 80 100 75 0 87,5 92 98 102 108 Frequency (MHz) 70 Pout @ 40V Vcc Pout @ 45V Vcc Pout @ 50V Vcc Efficiency @ 45V Vcc Efficiency @ 50V Vcc Efficiency @ 40V Vcc
Vcc "3" "2" "6" RF in RF out "5" "1" "4" Mechanical Layout Screws Type: Screws point 1-2-3-4-5-6 M3 Socket head cap screws + 6 Split lock washers WZ ø 3+ 6 Flat washers WZ ø 3 Thermal Compound Recommended Dow Corning 340 ( heat sink compound ) or equivalent
Application Note Read carefully the Following information, before design the system integration of this amplifier. Please remember that Italmec engineers are available to help customers in any Design activity. Note 1 (thermal exchanger requirements) Max operative temperature is measured very closed to the device flange. Max temperature value is referred to the nominal operative condition (Pout 600W VD 43V).In case of different working conditions, this limit can be different. Please provide an appropriate heatsink and a little air flow in the output transformer area. Please contact our technical department for further information. Note 2 (Load matching) This amplifier can work without power reduction on a 2:1 VSWR load matching. In this condition Phase and temperature are irrelevant. Please remember that this specification is valid only in CW or FM application, Pulsed signal or other kind of modulation can drastically change this limit. Since this amplifier is designed on a single RF device, under unmatching condition, power output can change up to +/- 1.5dB in function of reflected signal phase. Please foresee a current limiter in the supply system, to avoid device overstress. Note 3 (shielding) Due to the High gain of this pallet, a good shielding between final stage and any driver/low power stage is required. Please foresee a good RF choke also on the supply wiring. On request Italmec can provide an analysis on your line up. Note 4 (Overdriver) High driver level can damage this amplifier, design of equipment where the amplifier will be mounted, must foresee an appropriate protection circuits. Max input level is + 6Watt referred to the typical input power. Note 5 (efficiency) Amplifier efficiency is function of supply voltage, in order to obtain max efficiency please reduce supply in function of desired output power. leaving input power at about 5W. High voltage supply and low input power involve a sensible reduction in the efficiency. Please note that this amplifier is designed in order to have the best efficiency between 500 to 600W of output power, supposing this as typical working condition.
Note 6 (Protection) In order to take the amplifier safe in any working conditions, please add these protection in the final equipment. a)overdriver protection, if the input power exceed 8W average, the device can be damaged, please use an appropriate protection to reduce or switch off the input signal in case of overdrive. The amplifier can support higher power for short time, in according to the following graph. b) Reflected power protection (see note 2), a suitable protection system should switch off (or reduce) the input power in case of excessive reflected power.the following graph show the safety area Vs load mismatch @ full power c) thermal protection, switch off supply voltage if device flange temperature exceed 80 C when amplifier work at full power. In case of operation at low power, working temperature can be higher, however don t Exceed 170 C of junction temperature, to avoid a sensitive reduction in the amplifier MTBF. Junction temperature can be calculated using the formula Tj = Flange temperature + (device dissipated power*device thermal resistance).
assembling procedure Please follow this instruction to mount the pallet on the Main heatsink. Mounting procedure is very important, this because wrong coupling between pallet and heatsink surface can increase device temperature up to the destruction of device. 1)First of all please check heatsink surface, this must be very cleaned and extremely flat. Max unflatness +/- 0.4mm on the whole pallet surface and +/-0.03mm of roughness. 2)put a good quality thermal compound (raccomanded Dow corning 340) on the bottom side of carrier, in the device area. 3)apply the pallet to the final position then place over the device heat the pressure kit in this order: First the fiber glass spacing (in contact with device heat), then the rubber gasket and over all the alluminium bridge. Follow this tightening order, when all screw are inserted in the holes, first tighten the two device screw over the bridge, then the others on the pallet corners. 4) connect RF input/output and supply wire, then supply the amplifier in according whit note 5 (efficiency requirements) IMPORTANT NOTICE Italmec reserve the right to make changes to the product(s) or information contained herein without notice. Italmec assumes no responsibility for any errors which may appear in this document. Warranty information applicable to the product identified herein is available upon request. Nothing contained herein shall constitute a warranty, representation or guarantee of any kind. Italmec expressly disclaims all other warranties, express and/or implied including but not limited to warranties of merchantability, and of fitness for a particular purpose, use or application. No part of this document may be copied or reproduced in any form or by any means without the prior written consent of italmec.