The RF Power Labs 300-200A is a high-power RF amplifier built around the NXP MRF300 LDMOS transistor for single-ended operation in FM broadcast systems. It delivers 300W typical output power with peak performance exceeding 325W at 99MHz when supplied at 50Vdc, requiring only 3–4W of drive power. The amplifier operates across the FM band from 87.5MHz to 108MHz with 50-ohm input and output impedance and input reflectivity of −20dB. Thermal management via an external heatsink is essential for stable operation and device longevity.
Technical Specifications
• Transistor: NXP MRF300 LDMOS
• Frequency Band: 87.5–108MHz (FM)
• Maximum Output Power: >325W @ 99MHz (at 50Vdc)
• Typical Output Power: 300W
• Drive Power Required: 3–4W
• Input Reflectivity: −20dB
• Input/Output Impedance: 50Ω
• Power Supply: 28–50Vdc (48–50Vdc for full power)
• Operating Voltage: 48–50Vdc recommended; maximum 50Vdc
• Dimensions: 50mm × 82mm × 15–20mm height
– Key Features
• Single-ended architecture for straightforward integration
• Temperature compensation circuitry for stable output across operating conditions
• Low drive power requirement minimizes upstream amplifier demands
• Compact form factor suitable for space-constrained installations
• Requires direct heatsink contact to output transistor for thermal stability and to prevent oscillation
– Typical Applications
• FM radio transmitters (87.5–108MHz band)
• Communication systems requiring high RF output in the VHF band
• Radar and scientific research systems operating at FM frequencies
– Compatibility & Integration
• RF Connections: PTFE coaxial cable (RG178) for input and output; N female flange connector with RG142 or 0.141-inch semi-rigid cable recommended for installation
• Cable Routing: Keep RF leads as short as possible—a few millimeters preferred
• Thermal Interface: Flat heatsink surface with full transistor contact required
