Date: 19/06/2012
Cree's new GaN process G50V3 supports operating drain voltage up to 50V
Cree announces the qualification and production release of two new GaN processes: G40V4, a 0.25µm process with operating drain voltage up to 40V, and G50V3, a 0.4µm process with operating drain voltage up to 50V. Both technologies are compatible with Cree’s GaN MMIC technology on 100mm-diameter SiC wafers with a full complement of passive circuit elements and non-linear models.
The new processes are now available for development and full-rate production. With these processes. The G40V4 process has been qualified at both 28V and 40V operation with RF power densities up to 6W/mm of FET periphery with operation up to 18GHz. The G50V3 process has been qualified for 50V operation and RF power densities up to 8W/mm with operation through 6 GHz. Both of these processes are derivatives of Cree’s previously released G28V3 28V, 0.4µm process that has been in production since 2006 and exhibits one of the lowest field failure rates of any microwave technology in the industry, claims Cree.
Cree estimates that for a typical 3-sector, multi-band LTE/4G telecom remote radio head (RRH) installation, simply switching to GaN from conventional transistor technology could reduce RRH power consumption by up to 20 percent resulting in significant cost savings. The GaN benefits of higher voltage and higher efficiency allow smaller heat sinks and enclosures, less complex RF amplifiers and lower- cost AC-to-DC and DC-to-DC converters. Systems that previously required large fans to cool can now be air cooled.
The G40V4 and G50V3 processes can operate at a junction (channel) temperature of 225şC with a median life time of over two million hours (228 years), making these devices suitable for high reliability applications.
“Our customers have been asking for a reliable, higher-frequency process to exploit the advantages of GaN for applications greater than 6 GHz, including Satcom, radar and electronic warfare markets, and we believe our new G40V4 process successfully satisfies their needs,” said Jim Milligan, director of RF and microwave, Cree. “To address our customers’ need for lower cost GaN solutions, the 50 volt operating voltage of our new G50V3 process has been specifically engineered to provide an extremely low price in terms of dollars per watt of RF output power. The cost-performance of our G50V3 process is designed to rapidly accelerate the adoption of GaN in extremely cost-sensitive markets such as telecom infrastructure where GaN can now provide performance advantages not realizable in silicon LDMOS.”
“The higher operating voltage and higher efficiency possible with these new processes are key to rapid adoption,” said Dr. Cengiz Balkas, vice president and general manager power and RF, Cree. “Switching to GaN for upcoming LTE/4G macro-cell base stations could save telecom operators over $2 billion annually in reduced energy costs. Fortunately, the telecom industry is beginning to recognize these potential savings. Cree is targeting to deliver more than 75 million watts of GaN transistors into telecom base stations this calendar year.”
At 40 volt operation, Cree’s G40V4 process exhibits up to 6 Watts/mm PSAT at 18 GHz. Typical device characteristics at 10 GHz are 65 percent power added efficiency (PAE) and 12 dB of small signal gain. At 50 volt operation, the G50V3 process demonstrates up to 8 watts/mm PSAT at 6 GHz. Typical device performance at 3.5 GHz is 70 percent PAE with 12 dB of small signal gain.
Cree is releasing MMIC design kits with proprietary scalable non-linear HEMT models suitable for operation with Agilent’s Advanced Design System (ADS) and AWR’s Microwave Office simulator platforms. The design kits also contain a full suite of passive components—resistors, capacitors, spiral inductors and substrate ground vias that can be used to simulate full MMIC performance and provide significantly reduced design cycle times.