Wireless IC technology continues to evolve
As more and more wireless technologies become available in the marketplace (making them almost ubiquitous), users are demanding devices and services that automatically use the best available technology. Making things simpler, cheaper, and widely available are really what consumers are striving for. As we move into the technical details behind what end-users are asking for, things are not always as easy as they seem.
For wireless IC manufacturers, the main impact revolves around a single theme. That is, the movement of historically non-standard functions into cell phones (think Wi-Fi/VOIP, Bluetooth) and their impact in the design of the end product and the technology roadmap associated with those to achieve market demand.
The emerging trends, standards, and technological innovations that will affect wireless IC makers in the month ahead revolve around the:
MAC and digital baseband and the ability of those devices to support non-standard functionality, such as MP3. RF and mixed-signal transmit and receive path and the support of higher integration levels to reduce cost/price and form factor while enabling multi-mode and multi-band operations. Silicon technology requirements to support higher integration levels without jeopardizing lower power consumption. There''''s no doubt that the goal is a single-chip CMOS solution that''''s compatible with all standards and is capable of adapting itself. If this is the ultimate end-goal, we must first determine the signs indicating that we are on the right path.
CMOS technology''''s full potential wouldn''''t have been recently realized if only standalone radios were fabricated. The co-habitation of RF circuits and noisy digital circuitry on the same die was shown to be possible by proper circuit techniques, special deep nwell isolation structures, and exploitation of the digital substrate noise spectrum structure. In addition, multi-band radios require a large number of passive components that take considerable die area and are non-scaling components. This is currently being cleared as a side effect of creating new transceiver architectures and techniques based in complex RF passive networks and high-performance packaging solutions (or modules).
In addition, CMOS has enabled the technology to reach for higher clock frequencies (reducing the size of the RF passive network). In addition, the higher speeds offer other opportunities to compensate at the circuit level for intrinsic technology drawbacks.
The low-noise amplifier (LNA) was the first key component in which CMOS technology needed to prove it could work. The concern there was that the noise level could become progressively higher with lower geometries in such a way that the device''''s gain couldn''''t compensate and start to produce a higher noise figure. Fortunately, the device''''s transconductance, with typical RF device loading, provides higher gain with CMOS scaling down to compensate for additional noise in the channel. This should improve even more as frequencies go above 10 GHz.
