MRF8S18120HSR3 - 72W, 1.81GHz RF LDMOS | NXP | Cellular BTS
MPN: MRF8S18120HSR3 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $95 | $95.00 |
| 10 | $86.5 | $865.00 |
| 100 | $78 | $7,800.00 |
| 500 | $71.5 | $35,750.00 |
| 1,000 | $65 | $65,000.00 |
MRF8S18120HSR3 Overview
An RF power LDMOS transistor is a lateral double-diffused MOSFET optimized for high-frequency, high-power amplification in the 1 MHz to 3 GHz range. It belongs to the broader hierarchy of RF power transistors -> power transistors -> discrete semiconductors -> semiconductors. LDMOS devices replaced older bipolar and Si LDMOS technology in cellular base stations because they offer high gain, high efficiency, excellent thermal performance, and simplified biasing compared to bipolar junction transistors (BJTs).
Key features of the MRF8S18120HSR3 include 18.2 dB typical gain at 1.81 GHz, support for Class AB and Class C operation across all common cellular modulation formats, an integrated ESD protection structure, and NiPdAu-plated ceramic packaging for high-reliability surface-mount reflow assembly. The NI-780S package provides a low-inductance, low-thermal-resistance footprint suited to high-power pulsed and CW operation.
The lateral device geometry uses an N-channel enhancement-mode structure built on a silicon substrate with a high-resistivity epitaxial layer, providing high breakdown voltage and ruggedness into load-mismatch conditions typical of cellular antenna networks. At 28 V operation the device achieves high efficiency in Doherty and push-pull amplifier topologies used for modern macro-cell and micro-cell base stations.
Typical applications include GSM and GSM EDGE macro-cell base-station final-stage power amplifiers, WCDMA/LTE 1800 MHz driver stages, industrial RF heating, and high-power 1.8 GHz pulsed amplifiers. Its 72 W CW rating also makes it useful in DVB-T or other OFDM service transmitters operating in the same band.
When designing with this part, pay close attention to heat dissipation. A heatsink with sufficient thermal mass is required for continuous CW operation, and matching network design must follow the manufacturer reference design to achieve specified gain and efficiency. Always observe the 65 V drain-source breakdown maximum with adequate headroom margin.
This page synthesizes manufacturer datasheet parameters, distributor pricing, drop-in alternatives, and practical RF amplifier design notes not consolidated on the manufacturer datasheet.
Drop-in alternatives for MRF8S18120HSR3 — 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 MRF8S18120HSR3 (same form factor and footprint) — differing in RoHS Status, Frequency Range, Part Number, Manufacturer, Transistor Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MRF8S18120HR3
✅ Drop-In✓ In Stock
$54.2 / Unit
View Datasheet →MRF8S18210WGHSR5
✅ Drop-In📋 Reference alternative (not in catalog)
MRF8S21200HR5
✅ Drop-In📋 Reference alternative (not in catalog)
MRF8S26060HSR5
✅ Drop-In📋 Reference alternative (not in catalog)
AFT18HW355SR6
✅ Drop-In📋 Reference alternative (not in catalog)
MRF8S18120HSR3 Maximum Ratings & Electrical Characteristics
| Manufacturer | NXP Semiconductors |
| Part Number | MRF8S18120HSR3 |
| Transistor Type | LDMOS, N-Channel Enhancement-Mode Lateral MOSFET |
| Drain-Source Voltage (Max) | 65 V |
| Test Drain Voltage | 28 V |
| Test Quiescent Current (IDQ) | 800 mA |
| Operating Frequency | 1805 MHz to 1880 MHz |
| Center Frequency | 1.81 GHz |
| Output Power (CW) | 72 W |
| Power Gain (Typ) | 18.2 dB |
| Drain Current (Test) | 800 mA |
| Package Type | NI-780S |
| Mounting Style | Surface Mount (ceramic flange) |
| Operating Class | Class AB / Class C |
| Application | GSM / GSM EDGE cellular base station power amplifiers |
| RoHS Status | Compliant |
MRF8S18120HSR3 ni-780s Pin Configuration Guide
Pin configuration for MRF8S18120HSR3 (ni-780s package). This power device features gate, drain, and source terminals. For non-polarized packages, refer to the manufacturer datasheet for exact pin 1 orientation and footprint details. Common applications include power supply design, motor driving, and load switching.
No detailed pinout data available for MRF8S18120HSR3.
Refer to the datasheet for full pin configuration.
Safe Operating Area
Typical Applications
MRF8S18120HSR3 is suitable for 6 applications: GSM / GSM EDGE Base Station Power Amplifier, WCDMA / LTE Band 3 Power Amplifier Driver, Industrial RF Heating / Drying, DVB-T / OFDM Transmitter Final Stage, Radar and Pulsed-RF Amplifier, Public Safety / Private LTE Repeater.
GSM / GSM EDGE Base Station Power Amplifier
The MRF8S18120HSR3 delivers 72 W CW output power across the 1805-1880 MHz cellular band, making it an ideal final-stage or driver-stage PA for GSM and GSM EDGE macro-cell base stations. With 18.2 dB typical gain at 1.81 GHz and 800 mA IDQ at 28 V, it provides the high linearity and efficiency required for 8-PSK EDGE modulation while maintaining the ruggedness needed for VSWR mismatches at the antenna. Compared to lower-power LDMOS parts, the MRF8S18120HSR3's 72 W rating eliminates the need for power-combining two smaller devices in many macro-cell designs.
Recommended
WCDMA / LTE Band 3 Power Amplifier Driver
Although designed for GSM, the MRF8S18120HSR3's 1805-1880 MHz band coverage and 18.2 dB gain make it usable as a driver stage in WCDMA and LTE Band 3 base-station amplifiers. When biased in Class AB with proper DPD linearization, it can drive higher-output LDMOS final stages such as the MRF8S26060HSR5. The 65 V drain breakdown provides headroom margin for OFDM peak-to-average ratio excursions, while the NI-780S ceramic package ensures stable thermal performance under continuous downlink traffic.
Recommended
Industrial RF Heating / Drying
Industrial RF heating applications operating at 1.8 MHz ISM-adjacent frequencies can use the MRF8S18120HSR3 in CW or pulsed mode. Its 72 W CW power rating and high gain reduce the number of amplifier stages needed in 27 MHz or 40 MHz ISM-band heating systems when a frequency multiplier approach is used. The NXP reference design provides proven matching network topologies that engineers can adapt for industrial loads, with the LDMOS device's high ruggedness tolerating mismatched industrial heating loads.
Recommended
DVB-T / OFDM Transmitter Final Stage
Digital Video Broadcasting-Terrestrial (DVB-T) transmitters in countries re-using the 1800 MHz band can use the MRF8S18120HSR3 as a final-stage amplifier. Its high linearity at 72 W CW output supports the high PAPR of OFDM modulation when combined with crest-factor reduction techniques. Designers benefit from NXP's published reference designs and application notes for cellular, which directly translate to DVB-T amplifier chains with appropriate input matching adjustments.
Recommended
Radar and Pulsed-RF Amplifier
Pulsed-RF applications such as 1.8 GHz secondary surveillance radar or short-range industrial radar can use the MRF8S18120HSR3 in pulsed Class C operation. The 65 V drain rating provides headroom for high pulse voltages, and the NI-780S package handles pulsed thermal stress effectively. While the datasheet primarily specifies CW performance, the LDMOS device's high ruggedness supports pulsed operation with reduced duty cycle, enabling high peak power from the same 72 W CW-rated device.
Recommended
Public Safety / Private LTE Repeater
Private LTE and public safety repeaters operating in Band 3 (1800 MHz) can use the MRF8S18120HSR3 in donor-side or server-side amplifier chains. Its 18.2 dB gain supports high dynamic range with low noise figure when paired with a low-noise LNA upstream. The 72 W CW power supports high-density venue deployments such as stadiums and airports where repeater output must overcome building penetration loss.
Recommended
Recommended Products Summary
Engineering reference data for MRF8S18120HSR3 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MRF8S18120HR3 | MRF8S18210WGHSR5 | MRF8S21200HR5 | MRF8S26060HSR5 | AFT18HW355SR6 |
|---|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | NI-780S | NI-780S - same | NI-780S - same | NI-780S - same | NI-780S - same | NI-780S - same |
| Frequency Band | 1805-1880 MHz | 1805-1880 MHz - same | 1805-1880 MHz - same | 2110-2170 MHz | 2600 MHz band | 1800 MHz band |
| Output Power (CW) | 72 W | 72 W | 210 W | 200 W | 60 W | 355 W |
| Drain Voltage (Max) | 65 V | 65 V | 65 V | 65 V | 65 V | 65 V |
| Test Drain Voltage | 28 V | 28 V | 28 V | 28 V | 28 V | 28 V |
| Application | GSM/GSM EDGE BTS | GSM/GSM EDGE BTS | GSM/GSM EDGE BTS | WCDMA/LTE BTS | 2.6 GHz LTE | High-power 1800 MHz BTS |
Key Differentiators
- Proven 72 W CW performance at 1805-1880 MHz in NI-780S (vs MRF8S26060HSR5)
- Cost-optimized 1800 MHz PA versus higher-power variants (vs MRF8S18210WGHSR5)
- Same die as HR3 variant for sourcing flexibility (vs MRF8S18120HR3)
- NXP reference-design ecosystem (vs MRF8S21200HR5)
Design Notes
The MRF8S18120HSR3 dissipates up to ~100 W in 72 W CW operation with ~30% efficiency at 28 V. Estimated: at full CW output, the device requires a substantial heatsink with thermal resistance below 0.5 C/W to keep junction temperature below 200 C. The NI-780S ceramic flange must be mounted to a flat, clean copper or aluminum heat spreader with thermal compound; any gap from surface warpage creates localized hot spots that reduce long-term reliability.
Input and output matching networks must follow the NXP reference design layout exactly, with microstrip traces on the recommended PCB substrate (typically Rogers RO4350B or equivalent). The gate bias feed must be decoupled with a 10 uF electrolytic plus 100 nF and 10 nF ceramic capacitors placed as close to the gate pin as possible. Keep the gate bias trace physically separated from the drain RF path to prevent feedback oscillation at high gain.
Never operate the MRF8S18120HSR3 without proper RF input drive or into an open-circuited load - this can cause parametric oscillation that destroys the device. Always include an isolator or circulator at the output for VSWR protection. Ensure the gate bias is applied BEFORE the drain voltage during power-up sequencing to prevent the device from drawing uncontrolled current. Use a slow-start circuit on the gate bias supply to limit inrush current.
High-gain 18 dB LDMOS amplifiers at 1.8 GHz are susceptible to out-of-band oscillation if the matching network has poor stopband rejection. Add a low-pass or band-pass filter at the output to suppress harmonics at 3.6 GHz and 5.4 GHz. Shield the entire PA compartment with a machined or sheet-metal enclosure to prevent radiated emissions from coupling back into the input.
Compliance Information
RoHS compliant per NXP product page; REACH compliance not explicitly stated in available data. AEC-Q100 not applicable - this is an RF power MOSFET, not an automotive-qualified IC. Lead-free NiPdAu-plated NI-780S ceramic package.
