hf/rf ZONE Products for the week of March 17, 2003
Agere Systems says . . .
AGR21180E: Entry into the Base Station PA Market with
21 Products
World's Coolest Wireless Power Transistors Could Save Billions
of Dollars Annually for Wireless Service Providers
Agere Systems unveiled 21 breakthrough transistors targeting the wireless base station power amplifier market. Agere's innovative products--the world's coolest temperature wireless radio frequency power transistors--are targeted for third-generation (3G), 2.5 generation (2.5G), and second generation (2G) base station equipment.
Agere's power amplifier transistors can enable much cooler, smaller, and less expensive wireless base stations than are possible using any other RF power transistor technology. The transistors lower overall wireless amplifier and base station costs, and deliver lower capital and operating expenses for wireless service providers. Agere's products have the potential to save billions of dollars annually in combined operating and capital expenses for the wireless service provider industry.
In addition, Agere's new products help accelerate the industry trend to shrink the size and shift the location of today's typical base stations, about the size of a backyard toolshed and installed on the ground, to the size of a suitcase and installed above the ground on wireless antenna towers.
With these products, the company is the first to achieve the transistor temperature (thermal) performance level the industry has been striving to attain for the past 10 years. The transistors achieve 10-15 percent lower operating temperatures than all other competing transistors available today.
Agere's lower temperature transistors can cut in half the number of cooling fans in base stations compared with hotter transistor products. Reducing the number of fans also reduces noise pollution, a major issue in the base station market.
"The wireless transistor market represents an important new growth opportunity for Agere, and with our technological breakthroughs, we believe we are poised for success in this space," said Sohail Khan, executive vice president of Agere's Infrastructure Systems Group. "By delivering significant cost reductions, our new products will enable wireless service providers to accelerate delivery of lower-cost, feature-rich, high data rate services to cell phone users, such as video streaming, instant messaging and gaming. These products are a strong strategic fit with our existing portfolio for wireless base station manufacturers, and will allow us to further expand our position as a leading provider of components to the wireless infrastructure market."
Agere Making "Bold and Positive" Move
An RF power transistor is a packaged stand-alone electronic device roughly
the size of a nickel. The transistor is the key active building block on
power amplifier circuit boards, which are about the size of a laptop computer
and installed within base stations. The transistor boosts voice, data, and
video signals in various frequency ranges before the signals are delivered
to wireless subscribers. A wireless base station functions as the conduit
for routing, transmitting and receiving wireless voice, data, and video
signals. Agere is targeting sales of its product to manufacturers of base
stations who also build their own amplifiers, as well as companies that
manufacture amplifiers that are sold to base station manufacturers. More
than 20 companies are evaluating Agere's transistors.
"Entering this market is a bold and positive move by Agere that has resulted from the company's technical innovation and smart investment," said Edward Rerisi, a wireless semiconductor analyst with Allied Business Intelligence. "The potential performance gains enabled by these devices could yield enormous operational savings for existing technologies, while easing some of the financial burden of 3G deployment."
Two Breakthroughs
Agere's transistor technology consists of two key innovations aimed at improving
power transistor performance and reliability. The first innovation resolves
the issue of how to eliminate defects in chips when making ultra-thin silicon
wafers, which are roughly half the width of a human hair. Thicker chips
tend be warmer because they don't conduct heat as well as thin chips. Agere
created a proprietary wafer scale low cost, and high yield "die (chip)
thinning" technique that eliminates chip defects that occur using other
companies' approaches. Agere's method results in thinner and more thermally
efficient (cooler) chips.
Agere's technology breakthrough results in unparalleled transistor performance. They can be designed to be 30 percent shorter in length and are 50 percent thinner than all competing transistors. These thinner and shorter transistors get rid of heat more effectively than thicker and longer transistors.
The second advance improves the transistor's performance when amplifying
wireless signals. Using its patent-pending, high-density, low resistance
electrical connections, Agere created a transistor with reduced resistance
and parasitic capacitance. This leads to transistors with higher gain and
efficiency, two key parameters in selecting transistors for use in wireless
power amplifiers.
analogZONE Says . . .
The manufacturers of base stations have a goal that has been unachievable up to now, to get the final RF amplifiers for the systems right up with the antennas, removing the loss of the feeder in the gain equation for the final stage. The heat produced by those stages has meant that they have had to be given a great deal more space than that available at the top of the tower. One of my transmitter "huts" that I have access to - to maintain a couple of FM translators - recently had added a new base station for 1.8 GHz and the temperature in the building has soared by at least 15 degrees C.
Agere has rightly gone for LDMOS as a solution and then improved on the present processes to come out with parts that have heat performance at least 15% better than I have seen elsewhere. Since the LDMOS process came out of Japan there have been at least three vendors consistently working on improving it and Agere now makes it four.
Looking at the most challenging part in the new line-up - the AGR21180E, a 180-W part for 2.11 - 2.17 GHz we can see that the company has achieved a junction-to-case thermal resistance of 0.35 degree C/W and meets the 10:1 VSWR survivability needs. Data sheets were not made available to me but the product brief suggests that for typical 2-carrier 3-GPP W-CDMA systems the output power was 38 W with a 14-dB power gain, an efficiency (presumably PAE) of 26%, IM3 of -36 dBc, an ACPR of -39 dBc, and return loss of -12 dB (not stated whether input or output, both being internally matched in the module.) These are 28-V devices with Class 1 human body model ESD ratings.
As DAC performance improves there will be a tendency to allow the output devices to be less linear than are currently demanded by the system designers of base stations and devices, such as these from Agere, will be in a position to take advantage of running at even better efficiencies.
This family of 21 products for 900 MHz, 1.8 GHz and 2.1 GHz at different power levels increases Agere's penetration into the base station market and makes it more likely that a vendor can see a majority-supplier solution in many cases.
The AGR21180 is in both a surface-mount and a flanged module. All the new devices are shipping in sample quantities with volume production scheduled for the third quarter. Prices cover the spectrum of $12 to $207 in 10-k piece lots.