Nord, do you have any guess of what piece this pie spectrum might have
a chance at? I don't really know what spectrums role in basestations is. Do you know of any contracts we might have etc.. thanks danny
National eyes slice of $1.5B cellular-basestation pie
Stephan Ohr
SANTA CLARA, CALIF. - The cellular-basestation market is growing at a
rate of 20 percent a year by some estimates and National Semiconductor
wants a piece of it. What emerges with the rollout of its latest part-the
CLC5506 IF gain trim amplifier-is a coherent strategy for capturing what the
company sees as a $1.5 billion market in semiconductors.
"Some people might ask, 'What's a nice multimarket IC supplier like you
doing in a targeted market like cellular basestations?' " said Mark Levi,
National's director of analog marketing. "The truth is we do go after targets of
opportunity (where it makes sense), and we are capable of forward
integrating."
National's ability to assemble analog building blocks into more-integrated
devices elevated the LM78 temperature sensor into a PC-system health
monitor. Similarly, the company's ability to integrate 12-bit A/D converters
and ASIC microcontrollers put it in a competitive position against Analog
Devices Inc. (Norwood, Mass.) in the Taiwan-dominated
flatbed-scanner-chip market. Like ADI, National now sees an opportunity for
its data converters, RF downconverters and other high-frequency parts in the
burgeoning market for cellular basestations.
"There will be roughly 35,000 cellular basestations constructed this year, at a
cost of $250,000 each," said Kurt Rentel, citing figures from Electronic Trend
Publishing. Rentel is National's high-speed product line director in Fort
Collins, Colo. "That's an $8 to $10 billion market," he said. Roughly, 15
percent-$1 billion to $2 billion-will be in semiconductors, he estimates.
The kingpins in National's basestation offerings are a recently introduced
14-bit/52-Msample/second A/D converter (the CLC5958), a dual digital
downconverter (the CLC5902), variable gain amplifiers (the CLC5526 and
just-introduced CLC5506) and a complete five-chip diversity receiver. The
chips, fabricated in a 0.5-micron BiCMOS process (ABIC-5) with 15-GHz
bipolar fTs, are chief among the offerings National hopes will help it win a
position among cellular-basestation suppliers. "It's a big enough market," said
Rentel.
The goal among digital cellular-basestation suppliers is to reduce the size, cost
and power consumption of base-station receivers by digitizing the RF signals
directly and performing channel extraction, tuning and filtering digitally-to put
the A/D converter at the antenna, Rentel explained. "You can't do that right
now," he said. The sampling rate and bit resolution of current-generation A/D
converters only allow system builders to sample channels at the intermediate
frequency (IF) level. But then the digital basestation components will perform
additional downconversion, filtering, channel extraction and
decimation-moving the digitized voice (or data) signal down to a frequency
that can be manipulated by a DSP or analog baseband processor.
The heart of the system will be the A/D converter, Rentel said. That part must
have a high sample rate to take in a wide swath of channels (and multiple
carriers) at the intermediate-frequency range. It must also have a wide
dynamic range to capture weak signals in the fringes of a cell, or weak signals
in the presence of stronger ones. Ideally, a 90-dB dynamic is required to
support multicarrier reception. This would take a converter with a 16- or
17-bit resolution-and these are not available yet with sampling rates for IF,
said Rentel.
IF sampler
In the meantime, National's 14-bit/52-Msample/s A/D converter (the
CLC5958) and its 12-bit/65-Msample/s device (the CLC5956) offer support
for basestation designs. National said it is among the first to deliver a 14-bit IF
sampler. (Competitors in this area include ADI and Burr-Brown in Tucson,
Ariz.) National's 5958 consumes about 1.3 W of power in use, which may
seem high for a converter, but not for all the other functionality it provides,
Rentel said.
For multicarrier applications, National's five-chip Diversity receiver chip set
includes two digital variable-gain amplifiers that are adjustable in 6-dB steps
(the CLC5526), two 12-bit/65-Msample/s A/D converters (CLC5956) and
one dual digital tuner with automatic gain control (the CLC5902). The chip set
simplifies design by eliminating expensive analog IF stages. It supports direct
IF sampling up to 300 MHz, and meets GSM, Edge, PCS, DCS (GSM 1800
and 1900), Amps, Damps and PHS requirements.
The just-introduced CLC5506 variable-gain amplifier allows tweaking,
adjusting gain in 0.25-dB increments.
All basestation components are characterized for outdoor use (with an
industrial temperature range of -40 degrees C to +85 degrees C).
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