MRF8S18120HR3 - 1.8GHz 72W CW LDMOS RF Power Transistor | NXP
MPN: MRF8S18120HR3 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $78.5 | $78.50 |
| 10 | $72 | $720.00 |
| 50 | $65.5 | $3,275.00 |
| 100 | $60.8 | $6,080.00 |
| 500 | $54.2 | $27,100.00 |
MRF8S18120HR3 Overview
An RF power LDMOS transistor is a specialized MOSFET fabricated with a laterally-diffused drain structure on a silicon die, optimized for high-frequency, high-power RF amplification. LDMOS technology forms part of the broader RF power semiconductor hierarchy (LDMOS -> RF power MOSFET -> RF power transistor -> discrete semiconductor) and dominates cellular base station PA stages because of its high drain efficiency, broadband gain, and ruggedness into high VSWR loads.
Key electrical characteristics include a frequency range of 1805-1880 MHz, 18.2 dB typical power gain at 1.81 GHz, 72 W CW output power capability, a 28 V typical operating drain voltage, and a 65 V drain-source breakdown rating. The part is specified for class AB and class C operation across standard cellular modulation formats and is designed with internal matching to simplify PCB layout. Test conditions in the datasheet use 800 mA quiescent current and 28 V Vdd.
The MRF8S18120HR3 uses NXP's eighth-generation HV8 LDMOS process, which improves thermal performance versus earlier LDMOS generations and enables higher power density at 1.8 GHz. Its NI-780H ceramic package provides low thermal resistance and is optimized for high-volume, flangeless PCB mounting with screw-down heatsinking.
Typical applications include GSM and GSM EDGE macro base station final-stage PAs, micro/pico base station RF power stages, and 1.8 GHz-band industrial RF power amplifiers requiring high gain and rugged operation.
Designers should bias the device in class AB for linear GSM EDGE operation with proper heatsinking for the NI-780H flange and follow NXP's reference design evaluation PCB layout to achieve rated gain and efficiency at 1.81 GHz.
This page synthesizes distributor pricing, verified drop-in same-package alternatives, and practical RF design notes that go beyond the manufacturer datasheet to help RF engineers select and source this part quickly.
Drop-in alternatives for MRF8S18120HR3 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with MRF8S18120HR3 (same form factor and footprint) — differing in Part Number, Manufacturer, RoHS Status, Mounting Type, Operating Mode.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MRF8S18120HSR3
✅ Drop-In✓ In Stock
$65 / Unit
View Datasheet →MRF8S18120HR5
✅ Drop-In📋 Reference alternative (not in catalog)
MRF8S18120H-2
✅ Drop-In📋 Reference alternative (not in catalog)
PTFB182503FL
✅ Drop-In📋 Reference alternative (not in catalog)
QPD1023L
✅ Drop-In📋 Reference alternative (not in catalog)
MRF8S18120HR3 Maximum Ratings & Electrical Characteristics
| Manufacturer | NXP Semiconductors (formerly Freescale) |
| Part Number | MRF8S18120HR3 |
| Transistor Type | LDMOS, N-Channel Enhancement-Mode Lateral MOSFET |
| Frequency Range | 1805 to 1880 MHz |
| Output Power (CW) | 72 W |
| Power Gain (typ) | 18.2 dB at 1.81 GHz |
| Drain-Source Voltage (Rated) | 65 V |
| Test Drain Voltage (Vdd) | 28 V |
| Test Quiescent Current (Idq) | 800 mA |
| Drain Current Rating | 10 uA (leakage spec entry per datasheet) |
| Operating Mode | Class AB, Class C |
| Package | NI-780H (3-pin ceramic, flangeless) |
| Mounting Type | Surface Mount / Screw-down heatsink |
| Target Application | GSM, GSM EDGE base station PA |
| RoHS Status | Compliant per NXP product page |
MRF8S18120HR3 Pin Configuration
| Pin 1 | Drain — RF output / DC drain supply (28 V) |
| Pin 2 | Gate — RF input / gate bias |
| Pin 3 | Source — Source / RF ground / flange |
Safe Operating Area (estimated from datasheet CW ratings)
Typical Applications
MRF8S18120HR3 is suitable for 6 applications: GSM/GSM EDGE Macro Base Station Final-Stage PA, Micro/Pico Base Station RF Power Stage, 1.8 GHz Industrial RF Power Amplifier, Repeater and Bidirectional Amplifier Power Stage, Doherty PA Final Stage for GSM EDGE, Test and Measurement RF Power Amplifier.
GSM/GSM EDGE Macro Base Station Final-Stage PA
The MRF8S18120HR3 is designed primarily for GSM and GSM EDGE macro base station final-stage power amplifiers in the 1805-1880 MHz DCS-1800 band. With 72 W CW output power and 18.2 dB typical gain at 1.81 GHz, it provides the headroom needed to drive high-EPA (effective isotropic radiated power) sector antennas while maintaining class AB linearity for EDGE modulation. The internal matching network simplifies the PCB layout, reducing design cycle time. Bias is set at 800 mA quiescent drain current and 28 V Vdd for linear EDGE operation, or lower quiescent for class C CW GSM where efficiency exceeds 55%. The NI-780H ceramic package provides low thermal resistance for continuous 72 W operation at typical 50% drain efficiency, requiring substantial heatsinking but no exotic thermal management.
Recommended
Micro/Pico Base Station RF Power Stage
For micro and pico base stations operating in the 1800 MHz DCS band, the MRF8S18120HR3 delivers more than enough power at reduced quiescent bias, allowing the PA to operate in a backed-off, more efficient mode. Its HV8 LDMOS process provides higher gain than earlier NXP generations, which reduces driver stage complexity and BOM cost in small-cell designs. The 28 V Vdd allows direct connection to standard 24 V or 48 V telecom rails through a switching regulator. The NI-780H ceramic package supports compact PCB layouts required in micro base station enclosures, while the ceramic flange provides good thermal contact to a small aluminum heatsink.
Recommended
1.8 GHz Industrial RF Power Amplifier
Industrial RF applications in the 1.8 GHz band - including RF heating, plasma generation, and proprietary ISM-adjacent industrial telemetry - benefit from the MRF8S18120HR3's 72 W CW capability and 18.2 dB gain. The device is rated for continuous-wave operation and can be biased in class C for high-efficiency narrowband industrial use. Its 65 V drain-source breakdown provides ruggedness against load VSWR variations common in industrial installations where antennas may be subject to environmental stress. Designers should follow the NXP reference design PCB layout for stable operation at full CW power.
Recommended
Repeater and Bidirectional Amplifier Power Stage
Cellular repeaters and bidirectional amplifiers (BDAs) for the DCS-1800 band use the MRF8S18120HR3 as a final power stage to extend coverage inside buildings, tunnels, or rural areas. The part's 72 W CW output and high gain allow a single-device PA chain, simplifying BDA architecture and reducing DC power consumption. Its class AB linearity supports EDGE retransmission with acceptable spectral regrowth when properly linearized. The 28 V operation enables standard telecom 48 V rail supply via a buck converter.
Recommended
Doherty PA Final Stage for GSM EDGE
In a Doherty architecture for GSM EDGE macro base stations, the MRF8S18120HR3 serves as either the main or peaking amplifier at 1.8 GHz. Its 18.2 dB typical gain and 72 W CW capability allow the Doherty PA to deliver ~45 dBm composite power with high back-off efficiency, critical for EDGE modulation where peak-to-average ratios reach 4-5 dB. The HV8 process provides the thermal margin needed for continuous Doherty operation at full power. Bias sequencing between main and peaking devices is straightforward since both use the same gate bias network.
Recommended
Test and Measurement RF Power Amplifier
Test and measurement equipment designers building 1.8 GHz CW signal sources, EMC test amplifiers, or production RF test fixtures use the MRF8S18120HR3 as a final power stage. Its 72 W CW rating provides generous headroom for amplifier test beds, and its high gain reduces the required driver chain complexity. The datasheet's 1.81 GHz test fixture reference design can be adapted directly into lab test amplifiers. Class C bias offers high efficiency for CW test applications where linearity is not critical.
Recommended
Recommended Products Summary
Engineering reference data for MRF8S18120HR3 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MRF8S18120HSR3 | MRF8S18120HR5 | MRF8S18120H-2 | PTFB182503FL | QPD1023L |
|---|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | Infineon | Qorvo |
| Package | NI-780H | NI-780H - same | NI-780H - same | NI-780H - same | NI-780/OL-780 family | NI-780-compatible ceramic |
| Frequency Range | 1805-1880 MHz | 1805-1880 MHz | 1805-1880 MHz | 1805-1880 MHz | 1805-1880 MHz | 1805-1880 MHz |
| Output Power (CW) | 72 W | 72 W | 72 W | 72 W | 50 W (approx) | 50 W (approx) |
| Power Gain (typ) | 18.2 dB | 18.2 dB | 18.2 dB | 18.2 dB | 18 dB | 17 dB |
| Drain Voltage (Vdd) | 28 V | 28 V | 28 V | 28 V | 28 V | 28 V |
| Drain-Source Rating | 65 V | 65 V | 65 V | 65 V | 65 V | 50 V |
Key Differentiators
- Highest power in NI-780H family for 1.8 GHz GSM (vs MRF8S18120HSR3)
- Higher output power than Infineon equivalent (vs PTFB182503FL)
- Better gain than cross-brand 1.8 GHz LDMOS (vs QPD1023L)
- Tape-and-reel variant for high-volume assembly (vs MRF8S18120HR5)
Design Notes
At 72 W CW output and approximately 50% drain efficiency, the MRF8S18120HR3 dissipates roughly 70 W internally. The NI-780H ceramic package must be screw-mounted to an external heatsink or cold plate with thermal compound. Estimated: with junction-to-case thermal resistance of approximately 0.4 C/W and 70 W dissipation, the case must be held below 60 C to keep Tj under 100 C. Designers should follow the NXP reference PCB thermal layout for rated performance.
RF LDMOS devices are highly sensitive to PCB layout. Follow the NXP MRF8S18120H reference design PCB stackup and grounding scheme exactly. Input and output matching networks should use the datasheet-recommended microstrip dimensions on the specified substrate (typically Rogers RO4350B or similar). Gate bias traces must be kept short and decoupled with 100 pF and 10 nF capacitors close to the gate lead to prevent low-frequency oscillation.
Do not bias the MRF8S18120HR3 without RF input applied at full quiescent current - the device is rated for class AB and class C only, not class A. Exceeding the 65 V drain-source rating, even transiently during supply ramp-up, will destroy the die. Use sequenced gate-drain turn-on (drain brought up after gate bias is stable) to prevent inrush damage. Also avoid operating below the datasheet-recommended 1805 MHz - gain and efficiency degrade rapidly outside the characterized band.
Use a substrate with low RF loss at 1.8 GHz (Rogers RO4350B 0.5 mm or similar) for the matching network area. The NI-780H flange must be grounded with multiple vias around the package mounting holes to minimize lead inductance. Decouple the 28 V supply at the device with 10 uF, 1 uF, and 100 nF capacitors in parallel, placed as close as possible to the drain lead.
Compliance Information
RoHS compliant per NXP product page; RF power transistor not subject to AEC-Q100 (not automotive grade). Conflict minerals declaration per NXP corporate policy.
