The SRFT3034 (35W) RF Power Transistor is a high-frequency NPN silicon planar power transistor engineered for high-gain, high-efficiency RF power amplification in VHF and UHF communication equipment. Designed to deliver up to 35 Watts of continuous RF output power with excellent power gain, ruggedness, and high drain/collector efficiency, the SRFT3034 is widely utilized in FM broadcast transmitters, VHF/UHF mobile transceivers, amateur radio base stations, and industrial RF heating oscillators.

Specifications

• Part Number / Model: SRFT3034
• Transistor Type: NPN Silicon High-Frequency RF Power Transistor
• Package Type: Flanged Ceramic / Metallic Stud Package (High Thermal Dissipation)
• Output RF Power (Pout): 35 Watts (Typ. / Max across specified frequency bands)
• Operating Frequency Range: VHF / UHF Band (Typically 136 MHz to 500+ MHz / FM Band 88–108 MHz)
• Collector-Emitter Voltage (Vceo): ~18V to 36V DC (Supply compatible)
• Collector-Base Voltage (Vcbo): ~65V DC
• Emitter-Base Voltage (Vebo): ~4.0V DC
• Collector Current (Ic): Continuous ~4.0A to 6.0A Peak
• Power Gain (Gp): ≥ 10dB to 13dB (at rated frequency and supply voltage)
• Collector Efficiency (η): 60% to 75% in Class-C FM Operation
• Total Power Dissipation (Pd): ~60W to 80W (at heatsink base temperature Tc ≤ 25°C)
• Operating Junction Temperature (Tj): Up to +175°C to +200°C

Features

• High Power Output & Gain: Delivers a stable 35W output with low drive power requirements, simplifying pre-driver matching stages.
• High VSWR Ruggedness: Capable of withstanding moderate load mismatches and transient reflected RF power without immediate junction breakdown.
• Gold Metallization: Features gold-metallized die interconnects for superior reliability, thermal cycling endurance, and resistance to metal migration.
• Low Thermal Resistance Flange Base: Flanged design allows direct bolting to large aluminum/copper heatsinks for efficient heat evacuation during continuous carrier operation.
• High Collector Efficiency: High Class-C efficiency minimizes wasted heat energy and extends transistor service life in long-duration broadcast applications.

Common Applications

• FM Broadcast Transmitters: Final power amplifier stage for 30W–35W FM stereo transmitters (88–108 MHz).
• VHF/UHF Two-Way Radio: Mobile and base-station transmitters for marine, aviation, and public safety transceivers.
• Amateur Radio (Ham Radio): VHF 2-meter (144–148 MHz) and 70-centimeter (430–440 MHz) linear and CW/FM power boosters.
• Industrial RF Heating & Plasma Generators: High-frequency RF drive sources for laser excitation, medical diathermy, and RF induction.
• Driver Stage for High-Power Amps: Intermediate RF driver stage pushing kilowatt-class vacuum tube or multi-transistor pallet amplifiers.

Usage Tips

• Heatsink & Thermal Compound: Mount the transistor flange flat against a machined, deburred aluminum or copper heatsink using a thin, even coat of high-conductivity thermal paste.
• Even Mounting Torque: Tighten mounting screws evenly in alternating steps (recommended 0.6 to 0.8 N·m) to avoid warping the ceramic housing or cracking the internal silicon die.
• Impedance Matching: Use low-loss RF porcelain/mica capacitors (such as ATC 100B series) and high-Q silver-plated or thick enameled coils for the input/output LC matching networks.
• DC Supply Decoupling: Ensure generous RF choke inductors and low-ESR bypass capacitors are placed close to the collector feed line to prevent parasitic low-frequency oscillation and supply-rail ripple.

Datasheet