No slowdown in the basestation market....
commsdesign.com
For example, manufacturers of LDMOS transistors, typically used as the antenna drivers in cellular basestations, are reporting little slowdown. In fact, a short-term glitch in Ericsson Components' manufacturing process — which left the passivation layer of its LDMOS transistors vulnerable to temperature cycling — forced other manufacturers to fill the slack in an up-to-now-buoyant market, altering market shares at the end of 2000.
'Robust' sector
So UltraRF (Sunnyvale, Calif.) perked up its catalog offerings with second-sources of Motorola and Ericsson LDMOS parts. While much of its current consumption can be characterized as prototype productions (1,000 devices per week) in the service of one or two major customers, marketing vice president John Quinn insists he has seen no slowdown. Much of the new business is in the 2.1-GHz 3G arena, a sector he called "robust."
The two major problems facing LDMOS manufacturers are getting the costs down (dollars per watt) and increasing power density (watts per square inch). The current target is 300 W/inch2. "We're not quite there yet," said Quinn, "but that's what the world wants."
For LDMOS maker Xemod, (Santa Clara, Calif.) business has been so active that the company had to set up a new assembly facility in Tempe, Ariz., said marketing vice president Richard Clark. Xemod designs its own LDMOS parts but relies on foundries to make them. At MTT-S, Xemod demonstrated LDMOS-based power amplifier modules capable of delivering up to 350 W for wideband-CDMA applications. The modules have a 47-dB gain and are intended to simplify new-generation basestation design with a drop-in part.
"Much of the 3G stuff has been pushed out," Clark acknowledged. "It was too big a technology leap." But this left basestation manufacturers with a greater concern for the costs and efficiencies of their designs. Clark also believes the stretch-out of 3G introductions has created more support for Edge. Instead of 2 Mbits/s, basestation makers are seeing what they can do at 384 kbits/s.
In addition to low-power, 3-W LDMOS transistor arrays, Motorola was touting its new carbon-based silicon germanium process (SiGe:C). Motorola announced manufacturing qualification for the process in February. At MTT-S, the company announced the first product utilizing the process — a low-noise amplifier (LNA) with a built-in bypass switch. The switch allows large signals to bypass the LNA to prevent overload, said RF applications engineer Kelvin Leung. The switch device features low insertion loss (2.5 dB) and a low noise figure (less than 1.38 dB at 1.9 GHz).
|
