networkZONE Products for the week of July 8, 2002
Envara Says . . .
Transitional Object - Envara's WLAN RF Chip Offers
Multi-Mode IEEE 802.11a+b+g Interoperability On A Single Chip
Envara Inc. is sampling engineering silicon for its multi-mode
IEEE 802.11a+b+g EN303 RF chip. The EN303 is the world's first multi-mode
IEEE 802.11a+b+g on a single RF chip, offering interoperability with the
dominant IEEE 802.11a and IEEE 802.11b standards as well as the emerging
IEEE 802.11g draft that proposes higher data rates by employing OFDM in
the 2.4GHz band. OEM's will benefit from this advanced technology that enables
interoperability between the dominant WLAN standards and works over all
internationally defined WLAN spectral bands, including the additional 4.9
to 5.091GHz band recently proposed in Japan.
Given that the transition from 2.4GHz to 5GHz systems will not be immediate interoperability is a significant feature - freeing mobile users to access necessary data in any IEEE 802.11 wireless networking environment. The EN303's multi-mode IEEE 802.11a+b+g capability promises interoperability no matter what wireless networking environment you enter, while its coverage of all of the internationally allocated frequency spectra in both the 2.4GHz and 5GHz bands ensures transparent worldwide operation. "We expect to see a great deal of interest in multi-mode WLAN chips for the foreseeable future," said Craig J. Mathias, a Principal with the wireless advisory firm Farpoint Group. "Customers are looking for flexibility as WLAN technology continues to evolve."
The small die size Si-Ge chip has demonstrated extremely good performance in its first engineering silicon samples, which is a tremendous technological achievement for Envara's expert RF professionals as well as proof of the maturity and quality to IBM's SiGe process and modeling. " The fact that we were able to produce a high performance, production worthy RF chip in a single tape out, when RFCMOS chips can require as many as 6 to 10 such efforts, is a crucial advantage in this highly dynamic and fast growing market" stated Izik Kirshenbaum, Envara's President and CEO. Kirshenbaum also noted "our customers and end-users will highly benefit from our abilities to productize radios in a timely manner, not only for this generation but also for the longer term".
Envara is sampling chips for alpha customers, and will be demonstrating the technology in Japan and Taiwan in July and at N+I in September. Allen Nogee, technology analyst with In-Stat/MDR, noted "while most of the market was focused on single and dual-mode WLAN solutions using multiple chips, Envara stole a march on them all with their highly integrated, multi-mode IEEE 802.11a+b+g EN303. The fact that it also features low-power consumption, small die size and advanced patent-pending technology has significantly raised the standard in the WLAN arena."
Features of the EN303 chip
The EN303 chip is a highly integrated WLAN solution that integrates almost
all the required components onto a single chip through innovative design
and advanced, patent pending technology. The minimization of external components
while enhancing performance significantly reduces both chip and BOM costs
for OEM customers. A brief list of the primary features and advantages offered
by the EN303 include:
The EN303 is a unique combination of RF design and technology that enables
a first of its kind, low-power, low-cost, multi-mode IEEE 802.11a+b+g, single
chip solution capable of transparently operating anywhere worldwide.
analogZONE Says . . .
I reviewed Envara's preliminary announcement about a year ago and have anxiously been awaiting the emergence of further news while IceFyre, Bermai, Marvell, and a host of others announced their plans for domination of the wireless world. Now that Envara has some working silicon (or SiGe to be more precise), it looks like it was worth the wait. As we will see a bit later, the test results of their first-spin design are already delivering performance that should extend its range and robustness well beyond the IEEE minimum specs for both bands while many other 5-GHz chips (well, at least one) are struggling to just meet them.
The EN303 is the RF element of a two-chip, dual-band solution. It integrates the TX and RX paths for both 2.4- and 5-GHz bands of a fully-functional radio that will connect directly to Envara's CMOS baseband/MAC chip (due to sample late this year). This is a true dual-band, triple-mode chip that can support .a, .b, and .g modes, as well as all of the 5-GHz bands as low as 4.9 GHz (for the newly proposed Japanese band), and as high as the U.S. upper bands at 5.8 GHz. It contains all internal VCOs, PLLs, and most filter elements, and requires only a pair of inexpensive single-stage PAs to be popped onto a PCMCIA card.
I think that Envara made some smart up-front decisions that should at least make it a contender in this hotly-contested market. First, the decision to go with a SiGE front-end means that the RF section designers had lots of noise and gain margin to play with, rather than having to skirt the margins with an all-CMOS design. The high-quality on-chip passive components afforded by IBM's SiGe process also help cut price while improving performance. The subsequent reduced external component count, plus a higher yield (the early CMOS radios probably don't yield well at process corners) appear to more than offset the slightly higher cost of the SiGe process, while delivering the traditional low noise, linearity, channel selectivity, and power efficiency of a bipolar design.
The second smart move was to make the radio a true dual-band chip from the get-go. This contrasts with Atheros', Bermai's and IceFyre's philosophy, which is concentrated on the 5-GHz element and rely on "commodity chips" to add 2.4 GHz capabilities. While the world is swiftly moving to the 5-GHz band, I feel that there is still a great advantage to including 2.4 GHz capability in a current design - especially if it can be done for little extra cost. (For details on the 2.4 vs. 5 GHz debate, see what Dr. Protocol has to say in his most recent column.) Should a 5-GHz only solution be needed, it's easy to simply not populate the board with the external components needed for 2.4 GHz operation, and simply waste the $0.25 to $0.50 worth of silicon that won't be used on the chip.
Most of the radio appears to be relatively straightforward, but it does make clever re-use of as many elements as possible to avoid the bulk of two complete TX/RX chains for 2.4 and 5-GHz operation (for a closer look, you can click here to view their technical white paper.)
There are also a few "tricks" used to make this chip work, and one of them is a unique PLL design which delivers a very wide frequency range but maintains very tight frequency resolution, high stability, and a reasonably quick settling time - 200 microseconds. here is also the matter of their patented "EZ IF" elements which purports to be a novel direct-conversion mixer. I had spent quite a bit of time discussing this last year with Envara's Marketing Director, Paul Narflus, and pried enough information from him then that I was half-convinced that the chip would work, but not sure how well it would perform. Now that they have actually collected performance data from the first batch of chips, I must say that they have justified whatever faith I placed in them.
Paul McGoldrick and I looked at the actual results of lab tests on samples that they've had for a couple of months. The results were so good that they are now shipping the same chips to their first alpha customers rather than waiting for the second spin that they had anticipated.
Performance from these alpha chips seems to be very good with a receiver noise figure of 6 dB on both 2.4 and 5 GHz from antenna to baseband interface. As the sampling of numbers below shows, the receiver demonstrates specs that better the IEEE minimums with significant margins.
Specs like this should improve the chip set's real-world performance, allowing full-rate 64-QAM operation at longer distances, and under more crowded spectral conditions. The receiver's maximum dynamic range also exceeds the IEEE 802.11a spec, tolerating 15 dB more input power than required. This should allow better close-in operation in ad-hoc networks or near access points without saturating the receiver. Raviv Melamed, Envara's lead RF designer says that some of this margin comes from the fact that the chip began development with the intent of meeting the more stringent HiperLAN specs. Wherever it came from, it should pay handsomely in customer satisfaction.
Envara is sampling the EN303 radio chip to selected
customers now, and will deliver their baseband/MAC solution late this fall.
Pricing for the two-chip radio and baseband/MAC chip set will be under $30,
in quantities of 100 k.
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