Freescale LDMOS RF Power Transistors Optimize Performance of Wireless Base

Freescale Semiconductor introduced seven LDMOS RF power transistors that deliver exceptional performance and enable WCDMA and CDMA2000 base station transmitters to exploit the full potential of the Doherty amplifier architecture.

Fast becoming an industry standard, the Doherty architecture offers exceptional efficiency but presents design challenges due to conflicting requirements for both high efficiency and high linearity. Designed specifically for the architecture, the new Freescale transistors successfully address these challenges, thereby enabling the creation of base stations that consume significantly less power than those using traditional transistor designs.

Two of the devices operate in the 865 to 960 MHz band, two in the 1930 to 1990 band and three in the 2110 to 2170 MHz band, covering the most popular cellular, PCS and WCDMA frequencies.

The new devices include:

• MRFE6S9205H/HS: 865 to 960 MHz, 58 W average output power, 20.5 dB gain, 34% efficiency, ACPR of -38 dBc (5 MHz offset, 3.84 MHz channel)

• MRFE6S9135H/HS: 865 to 960 MHz, 39 W average output power, 20 dB gain, 34.5% efficiency, ACPR of -38 dBc (5 MHz offset, 3.84 MHz channel)

• MRF6S19200H/HS: 1930 to 1990 MHz, 58 W average output power, 17.2 dB gain, 29.5% efficiency, ACPR of -38 dBc (5 MHz offset, 3.84 MHz channel)

• MRF6S19140HR3/HSR3: 1930 to 1990 MHz, 29 W average output power, 16 dB gain, 27.5% efficiency, ACPR of -51 dBc (885 kHz offset, 30 kHz channel)

• MRF7S21170HR3/HSR3: 2110 to 2170 MHz, 50 W average output power, 16 dB gain, 31% efficiency, ACPR of -37 dBc (5 MHz offset, 3.84 MHz channel)

• MRF6S21190HR6: 2110 to 2170 MHz, 54 W average output power, 16.4 dB gain, 30% efficiency, ACPR of -38 dBc (5 MHz offset, 3.84 MHz channel)

• MRF6S21140HR3/HSR3: 2110 to 2170 MHz, 30 W average output power, 15.5 dB gain, 27.5% efficiency, ACPR of 41 dBc (5 MHz offset, 3.84 MHz channel)

Available on tape and reel, all of the devices operate from a +28 V supply and feature integral ESD protection. They are designed to handle a 5:1 VSWR without damage and are housed in RoHS compliant, high thermal-conductibility air-cavity ceramic packages.

“The Doherty amplifier’s inherent high efficiency can help reduce a base station’s annual power consumption when compared to other amplifier types, thus allowing Freescale to deliver to our service provider customers the least costly product to operate,” said Gavin P. Woods, vice president and general manager of Freescale’s RF Division. “But to achieve its full potential, Doherty amplifiers require RF power devices specifically tailored for their needs. Freescale is the first company to deliver these Doherty-optimized, high efficiency power devices, which are designed from the ground up to make the most of this unique type of amplifier architecture.”