Motorola Qualifies Enhancement-mode GaAs Technology for Single-Supply Wireless Transmitter and Receiver Circuits
Source: Motorola
Provides high power density and efficiency, with excellent linearity and noise figure
Phoenix, AZ, Motorola s (NYSE:MOT) Semiconductor Products Sector, one of the world s largest suppliers of radio frequency Gallium Arsenide (RF GaAs) circuits, has completed qualification of its true enhancement-mode (E-mode) heterostructure field effect transistor wafer process. This advanced single power supply GaAs process is engineered to provide exceptional, and cost effective performance in both linear transmitter and receiver circuits for low-voltage portable wireless applications.
"Motorola s advanced E-mode GaAs technology provides advantages over depletion-mode pseudomorphic high electron mobility transistor (pHEMT) devices," said Karl Johnson, director of Motorola s Compound Semiconductor Technologies Laboratory. "Because of its low off-state leakage current, this true enhancement-mode device allows elimination of the drain-supply switch required for depletion-mode pHEMT and metal semiconductor field effect transistor (MESFET) devices."
The high power density and efficiency, excellent linearity and noise figure, plus the reliability performance of this E-mode GaAs technology make it a logical choice for future wireless applications. This technology is ideal for use in transmitter and receiver circuits, for both analog and digitally modulated portable products.
"Single-supply power amplifiers have become the new paradigm in portable phone handsets due to the recent availability of near-zero threshold voltage pHEMT and heterojunction bipolar transistor (HBT) technologies. The need for decreasing product cost and size is also a high priority. The E-mode GaAs technology helps to reduce the cost and size of the end product by eliminating both the negative voltage generator and the drain-supply switch within the handset power amplifier section, as well as eliminating additional passive components," said Jim Oakland, manager of design and technology for Motorola s Wireless Transmitter Solutions Division.
A three-stage power amplifier designed for a 1900 MHz TDMA application has delivered +30 dBm output power, 42% power-added efficiency, adjacent channel power of -30 dBc, and alternate adjacent channel power of -48 dBc. Another key feature of this E-mode technology is a high Schottky turn-on voltage of +1.8 V at 1 mA/mm, compared to +0.8 V for a comparable depletion-mode or near-zero threshold pHEMT device. A high turn-on voltage is desirable for power amplifier applications to raise the output power capability of the device, while reducing the amount of gate current developed under high RF drive levels.
This E-mode technology has also demonstrated excellent noise figure and linearity performance for small signal applications. At 900 MHz, a single-stage amplifier achieved a noise figure of 1.2 dB with an associated gain of 18.5 dB. Impressive linearity performance was also achieved in this single-stage amplifier due to the technology s linear gm (transconductance) characteristic.
First products using this E-mode GaAs technology are expected to be available to the merchant market in February of 2001. As with all of our other GaAs ICs, these new devices are scheduled to be manufactured in Motorola s Compound Semiconductor-1 (CS-1) six-inch wafer fabrication facility in Tempe, AZ. The CS-1 fab completed conversion from four-inch to six-inch wafers in June 2000, making it the largest RF GaAs facility in the world.
As the world s number 1 producer of embedded processors, Motorola s Semiconductor Products Sector offers multiple DigitalDNA™ technologies which enable its customers to create "smart" products and new business opportunities in the networking and computing, wireless communications, transportation, and imaging and entertainment markets. Motorola s worldwide semiconductor sales were $7.4 billion (USD) in 1999. http://www.motorola.com/semiconductors Motorola, Inc. (NYSE:MOT) is a global leader in providing integrated communications solutions and embedded electronic solutions. Sales in 1999 were $33.1 billion. http://www.motorola.com MOTOROLA, the Stylized M Logo and all other trademarks indicated as such herein are trademarks of Motorola, Inc.
Contact: Motorola Bob Benzer Tel: 480 413 3840 RTN180@emial.sps.mot.com Or Angela Hatfield Tel: 480 413 4260 RVNC10@email.sps.mot.com
MotorolaBob Benzer
Tel: 480 413 3840
RTN180@emial.sps.mot.com
Or
Angela Hatfield
Tel: 480 413 4260
RVNC10@email.sps.mot.com
E-mail: RVNC10@email.sps.mot.com
Web site: http://www.motorola.com
