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Mixed signal processing is the hottest trend in internal wireless technology - just ask Lucent, TI and Motorola.
One of the hottest trends in microelectronics for wireless these days is mixed signal processing - the integration of analog and digital componentry on single "superchips" that reduce power consumption, boost call quality and, theoretically at least, lower the number of parts required to make a wireless handset.
Four major companies are at the forefront of digital signal processing (DSP), radio frequency (RF) and mixed signal research for wireless: Lucent Technologies' Microelectronics Group, Analog Devices, Texas Instruments and Motorola. In recent years, creating a unified digital baseband chip platform has been a goal. From five chip baseband architectures with 5-volt operation and one- to one-and-one-half-hour talk times (1990), wireless terminals now use single chipsets for digital and analog baseband, some supporting five hours of talk time with 3-volt operation. Mixed signal chipsets are coming on strong, and will alter the economics - and architectures - of next-generation, data-intensive wireless systems.
Each of the wireless chip leaders leverages a particular strength, according to Will Strauss, president of Forward Concepts (Tempe, Ariz.), a market research firm specializing in the semiconductor industry. "Analog Devices has some of the more advanced RF front ends right up near the antenna; the front ends are complete with analog-to-digital converters," he says. "Texas Instruments [TI] is stronger in digital processing than mixed signal, and Lucent is a little more balanced between the two. The other supplier, Motorola, is a strange beast with its own captive semiconductor factories. They also buy DSP chips from Lucent and TI in addition to their own."
Each company approaches the mixed signal challenge from a slightly different angle. Texas Instruments, for example, values an architecture for componentry - aggregation of analog components with other analog devices; integration of digital components together - that satisfies cost-reduction demands of the market as it exists. Lucent is pushing a vision of mixed signal processing that relies on leapfrogs in manufacturing technology.
TI outlines the following semiconductor trends:
* Reduced geometries to .18 micron ([[micro]meter]) level and beyond
* Increased DSP processing power to the 200-400 MIPs range;
* Chips with power consumption at roughly the 1-volt level (currently 3 volts are common); and
* Improved integration techniques, allowing for more cost-effective chip memory and key analog functions.
The following are excerpts from exclusive interviews conducted with Aaron Fisher, general manager-wireless products for Lucent's Microelectronics Group; Christian Dupont, marketing director for TI's North American wireless communications business unit; Tom Wrappe, director of strategic planning for the TI …