SSS is proud to present our Thirteenth Online issue.
We are now soliciting ideas and articles for our fourteenth issue, which is tentatively scheduled
for spring 2005. Please send your comments and suggestions to:
What's New At Pegasus Technologies
and SSS Online
Our Upcoming Move: Progress Report
As we reported in our last issue, we have signed a lease on a new building that is being constructed
on a 4.6 acre parcel in the Roane Regional Industrial and Business Park, less than a mile away
from Interstate 40, close to both Knoxville and Oak Ridge, Tennessee. When we have moved in, we'll
all finally be in one spot -- for now, we're scattered in 4 different locations in a 20-mile radius.
Construction is underway. We broke ground on October 18th in a pouring rainstorm -- and rain has plagued
us ever since. Despite the soggy conditions, the walls are completed and work on the roof has begun.
We are very excited about this move, which is currently scheduled to take place in early March (if it
stops raining long enough to get the building under roof...). Check our
facilities page for updates.
Groundbreaking Ceremony, 10/18/04
Pegasus Technologies building, 12/3/04, side view
We Helped Record History! (Part 2)
By now everyone knows that Burt Rutan's Spaceship One won the Ansari X prize on October 4
for its two flights to space within a fourteen-day period. We played a small part in recording
this historic event -- the pictures of the takeoff and landing taken at the runway were
transmitted over a Pegasus Technologies wireless video link design!
You can see the videos here.
The End of a Good Year; Thoughts for the Next
At this time of year, it's good to take a moment to reflect and think about the future. 2004 was
a really good year for us. On the Pegasus Technologies side, we added three new staff members,
outgrew our facilities, doubled our 2003 gross sales, and completed development of two new
products (see our RF Module Sales page for a description and pricing).
For 2005, we have some very exciting developments in the works, but it would be premature to
mention them until plans are finalized. However, we anticipate that 2005 will be a strong growth
year for us. In today's uncertain world, we are very grateful for your continued support and
confidence, and we will continue to strive to deserve your trust.
On the SSS Online side, we have completed our fourth year operating the Spread Spectrum Scene
website. Our statistics have increased substantially during the year, both in the number of
hits and the number of visits. Our Google ranking and placement on top search engines has continued to improve and
we are now at or near the top on most of our search terms. We have updated every one of the
more than 400 active pages at least once during the year, and have added a huge amount of new
material as well as finishing the upload of the old 1992 and 1993 paper issues. We plan for
more of the same in 2005.
We hope that each and every one of you has a peaceful, safe, and successful year in 2005. As
always, we welcome any comments or suggestions on any aspect of our website.
Chip Review: The Toshiba
TB31262F Wireless Telephone Chip
By Jim Pearce
Jim Pearce is Chief Technical Editor of SSS Online, and President of
of Pegasus Technologies, Inc., a
provider of electronic RF and advanced electronic design services and RF modules.
Sometimes you find a chip that does so much more than its original intended function
that it is hard to keep from using it. This is how I felt about the Toshiba TB31262F
wireless telephone chip. The '262 is a complete RF section for a full duplex analog
FM transceiver that also has data communications capability. It is intended to
operate in the US 902 MHz to 928 MHz license-free band but with a minor change in
external components it can also operate in the European 868 MHz band.
Note that even though the datasheet is all English, the pdf file contains codes for
Japanese characters and Acrobat Reader will complain. Go ahead and load the Japanese
character set when Acrobat complains.
Transmitter
Lets take a look at the transmit side of the '262.
The transmitter uses a phase locked loop frequency synthesizer. Frequency modulation
of a PLL can be performed either by summing the modulation voltage with the VCO control
voltage, or by varying the reference frequency for the PLL. Which of these techniques
is used has a direct impact on the choice of the loop bandwidth of the PLL. The '262
uses the first method of modulation since it must simultaneously transmit and receive,
and having the referee frequency modulated would make receiving using the same reference
impossible.
This means that the loop bandwidth of the PLL must be lower than the lowest desired
modulation frequency. Modulation with frequencies lower than the loop bandwidth will be
cancelled out by the feedback action of the PLL. This is the reason for the relatively
large values of the components the make up the transmit loop filter, C11 (1uF), R6 (1K), and C12 (2.2uF).
The voltage controlled oscillator for the transmitter operates at half the desired
output frequency and is completely integrated except for two inductors. These inductors
have a suggested value of 2.2 nH but for operation at lower frequencies such as the European
868 MHz band you may need to use 2.7 nH.
The '262 includes two stages of amplification for the audio signal prior to its application
to the VCO modulation varactors. The first stage is a straightforward op-amp that is AC
coupled on its input. The output of this stage is available to the designer, but it is also
internally connected to a audio level compressor.
The compressor on the transmit side works in conjunction with a matched expander on the
receive side to increase the apparent dynamic range of the FM communications channel. A
compressor and expander together is called a compandor. More information on the theory
and operation of compandors can be found in Philips Application Notes
AN174
and AN176.
If compression of the audio signal isn't desired, the output of the first amplifier can
be connected to the second amplifier without going through the compressor. On the
schematic this would involve connecting C8 to pin 8 instead of pin 7.
If you want to send data using the '262 you simply sum in the data signal with an additional
resistor to pin 6. The value of this resistor must be sized so that the digital signals
voltage modulates the signal an appropriate amount. You should also keep in mind that
the op-amp between pins 4 and 5 will invert the data signal so that a data high level will
cause a shift to the low frequency and a data low level will cause a shift to the high frequency.
The format of the digital data that you use to modulate the transmitter with will have an
impact on how well the system works. Since the system is AC coupled, you should give
serious consideration to using Manchester encoding. For more information of Manchester encoding see:
Wikipedia's Article.
We have used low bit rates of about 2400 bps, though the '262 should be capable of much higher rates.
The modulated PLL signal passes through a frequency doubler stage and then a power amplifier stage.
The power amplifier has a differential output which must use external components to perform the
function of a balun (balanced-to-unbalanced). This RF output must then be fed through a bandpass
filter. We at Pegasus have found that a SAW filter works best for this. In a cordless telephone
application a SAW duplexer is often used.
A duplexer is a pair of filters and a RF combiner. It has two inputs and one output. The inputs
are responsive to frequencies at opposite ends of the 902 - 928 MHz band. So you might have
the transmit side operate at 903 MHz and the receive side operate at 927 MHz.
Receiver RF Section:
The receiver in the '262 is amazingly sensitive. We have had good luck with it at signal
levels of less than -90 dBm! The input signal is amplified by a low noise amplifier stage
and then fed to a double balanced mixer. The local oscillator for the mixer is supplied
by a phase locked loop that operates off of the same reference frequency as the transmitter
PLL. The receiver PLL does not need to be modulated so its loop bandwidth can be higher
so that the phase noise can be reduced. Notice the smaller values of the loop components,
C28 and C27.
The output of the mixer is a 10.7 MHz intermediate frequency (IF) signal. This signal is
routed through standard ceramic filters like the Toko SK107 series
or the Murata SFECS10M7 series or SFECV10M7 series,
and is amplified by three stages of IF amplifiers. The amplified IF signal is then routed
to the demodulator.
Receiver Baseband:
The IF signal is demodulated using a quadrature demodulator stage. The quadrature coil
can be a standard IF can with a tuning slug or a ceramic demodulator. We have had good
performance using the Murata CDSCB10M7 series of ceramic demodulators. The advantage to using
these is that no turning is needed.
The demodulated audio signal is available on pin 47. Filtering of this signal is
performed by R13 and C35 before it is amplified and expanded. The output of the
expander goes through a volume control stage whose gain can be set digitally. This
signal can them be further amplified by the speaker driver amplifier.
The audio signal also can be routed into pin 45 to perform data slicing. This gives
a digital output signal on pin 24 that can be routed into your microcontroller for
further processing.
Getting Started with the TB31262F
I have found that this chip is popular in 900 MHz cordless telephones. When I first
started using it, I bought a Radio Shack® catalog number 43-3534 cordless telephone
for less than $20. I used its FCC identifier on the
FCC equipment authorization database
to find its certification data and was able to download the phone's schematic.
I could then remove the microcontroller that is in the phone and connect my own. This
made a very inexpensive development evaluation board for the TB31262F!
At press time, there is no movement on either side of the standards debate over multiband OFDM vs.
direct sequence spread spectrum as the path forward for UWB. Both camps are proceeding as quickly
as possible to churn out silicon and get them into products -- and on this front, the direct
sequence camp has the lead. There's lots of activity going on right now, especially with the FCC
weighing in on UWB with a second Report and Order that expands wideband use in certain frequency bands.
Below is a compendium of press releases, FCC releases, and other news items on this topic.
FCC Amends Rules to Permit Wider Application of UWB in Non-Restricted Frequency Bands
On December 15, the FCC issued a Second Report and Order on UWB. In response to a Multispectral
Solutions petition, the FCC agreed to permit new unlicensed wideband
devices in the 6 GHz, 17 GHz and 24 GHz bands. This gives MSSI a huge leap forward in its
ability to go forward on a wide variety of applications. Carefully distinguishing these wideband devices
from UWB, the Second Report and Order dismissed a Petition for Reconsideration filed
by the Satellite Industry Association, stating that it would continue to monitor the
situation in the 4 GHz band, and also denied the Petition for Reconsideration filed
by Cingular, Inc. In so doing, the FCC reaffirmed its decisions regarding UWB adopted
in the first UWB Report and Order.
For more information, click on the links below:
MSSI's press release, "Multispectral Solutions Receives FCC Approval
for Expanded Use of Ultra Wideband Devices," Business Wire, 12/15/04.
MBOA Ultrawideband Techzone Showcases UWB Products and Applications at CES
LAS VEGAS, Dec. 16, 2004 - Sixteen of the world's leading semiconductor,
personal computing and consumer electronics companies along with four key
wireless industry organizations will appear together in the MultiBand OFDM
Alliance (MBOA) Ultrawideband TechZone in the Innovations Plus area of the
2005 International Consumer Electronics Show (CES), Jan. 6-9, in Las Vegas.
The intent of this cooperative appearance is to excite and educate the CES
audience about ultrawideband (UWB), a revolutionary high-speed, short-range
wireless technology with enormous potential for consumer electronics slated
for release as early as the second half of 2005. The TechZone will also show
the broad industry support for MBOA ultrawideband technology.
"By collaborating today, the 170-plus members of the MBOA-SIG together with
the WiMedia Alliance, Wireless USB Promoter Group and 1394 Trade Association
are demonstrating a high degree of broad industry commitment and cooperation
for the MBOA UWB technology," said Stephen Wood, technology strategist for
Intel R&D and a member of the MBOA-SIG promoter group. "This industry
convergence around a single technology helps to ensure seamless
interoperability between future products and will fuel the creation of a
robust and fast-growing market."
The MBOA Ultrawideband TechZone will include eight live demonstrations of
the wireless technology including bulk data transfers, quality-of-service
based streaming video from various sources using wireless USB and wireless
IP approaches.
The exhibiting companies in the TechZone will include: Alereon, Commstack,
Focus Enhancement Semiconductors, General Atomics Advanced Wireless Group,
HP, Intel Corporation, Mitsubishi Electric, Orangeware, Philips Electronics,
Staccato Communications, Samsung Electronics, Texas Instruments, Taiyo Yuden
R&D of America (TRDA), TDK, WiQuest and Wisair.
The exhibiting specification-building bodies, who are closely working
together to ensure interoperability for MB-OFDM ultrawideband products, will
include: the MultiBand OFDM Alliance (MBOA-SIG), WiMedia Alliance, 1394
Trade Association and the Wireless USB Promoter Group.
Other News
Sony Playing both sides of the UWB Fence?,
Patrick Norton, Xtreme Tech, 12/17/04 Sony, a key player in the MBOA, is rumored to be demonstrating a direct
sequence UWB chip at the International Solid-State Circuits Conference in February 2005.
Staccato Demonstrates Industry's First Complete Single-Chip All-CMOS MBOA
UWB Chip
San Diego, Calif., December 14, 2004 - Staccato Communications, wireless USB
and ultrawideband (UWB) wireless silicon leader and pioneer, announced today
that it has demonstrated to select customers the first version of Staccato's
single-chip design for all major components of the RF and baseband specified
by the newly completed MBOA PHY specification. This single-chip design is
the latest in a series of all-CMOS test chips built by Staccato over the
past 18 months but is the first to include all major components specified by
the newly finalized MBOA specification. The chips have demonstrated the
ability to transmit at the highest specified data rate of up to 480 Mbps.
The all-CMOS implementation clears the path for low-cost, highly integrated
silicon solutions for wireless USB and other UWB applications by taking
advantage of mainstream generic CMOS foundry processes.
"In terms of what it means for consumers, this achievement is significant,"
said Joyce Putscher, director and WPAN principal analyst for In-Stat/MDR.
"Those familiar with the history of the Bluetooth and Wi-Fi markets can bear
witness to the fact that all-CMOS solutions enable these technologies to be
integrated into end products more quickly due to their significant price
advantage. This can translate to early market share capture."
"We are pleased by the results we have seen in the series of MBOA UWB test
chips we have built so far," said Roberto Aiello, president and CEO,
Staccato Communications. "We are now comfortable moving to production
samples of the single-chip PHY for our customers as the next step and then
quickly integrating the MAC and wireless USB functionality for a complete
single-chip wireless USB chip in 2005."
Staccato Communications' single-chip PHY products are expected to sample in
early 2005, ready to accelerate retail PC, consumer electronic, and mobile
phone products to market with ramping production later in the year. Complete
single-chip wireless USB silicon will sample in late 2005. Both products
will be available with complementary development kits to key customers.
CARLSBAD, CALIF- December 13, 2004 -- Pulse~LINK, Inc. announced today
that it has achieved the highest data rates ever transmitted and received for
Ultra Wideband (UWB) wireless communications, demonstrating 667 Mbps of
throughput after forward error correction. The new high-speed chipset
architecture, capable of surpassing one Gigabit, presents CE manufacturers
with DVI, HDMI and 1394b cable replacement opportunities for
interconnectivity of high-end multimedia devices and wireless streaming of
HDTV.
"Our actual over-the-air data rate is at present 1.3 Gbps per second, with
the data throughput presently at 667Mbps", states John Santhoff, Founder
and CTO. "Over the next thirty to sixty days, optimization will bring the
throughput to Gigabit data rates."
Pulse~LINK will begin making Gigabit wireless UWB evaluation kits available to
partners in February 2005. The company's Gigabit RFIC is presently in
fabrication and evaluation kits based on the sample RFIC are planned for
release in April 2005. In addition to its high speed UWB technology,
Pulse~LINK is introducing a new forward error correction technology for
wireless communications that is far more efficient at extremely high data
rates than the Viterbi forward error correction technology commonly used in
other wireless communications.
The high data rates achieved with Pulse~LINK's chipset will enable the first
wireless solutions for DVI (Digital Visual Interface), HDMI (High Definition
Multimedia Interface) and 1394b (Firewire) cabled devices. Cable
replacement for these "video centric" interconnect technologies will allow
wireless streaming of HDTV and high quality multi-channel audio for home
theater systems. DVI, HDMI and 1394b are also used to interconnect
multimedia electronics such as projectors, set-top boxes, high quality DVD
players, video cameras, home theater systems and more.
Along with providing higher data rate solutions, Pulse~LINK is pioneering
longer-range UWB transmissions for Wireless LANs. "One of the primary
requests we've heard from consumer electronics manufacturers of flat panel
and high-end displays is for picture-in-picture HDTV wireless transmissions at
25 meters through at least one wall, which we have demonstrated." states
Bruce Watkins, Pulse~LINK President and COO. "Pulse~LINK currently offers
the only solution capable of sending multiple streams of HDTV wirelessly
beyond a single room."
In recent demonstrations, Pulse~LINK transmitted two simultaneous HDTV
signals for "picture-in-picture" television through a combined seven inch thick
concrete wall and an additional steel-frame drywall at ten meters and has
demonstrated the same two streams at distances of 25 meters through one
steel-frame drywall.
FCC Certifies Ubisense's UWB, By Mary Catherine O'Connor, RFID Journal
Dec. 13, 2004. One of the first outlets of ultra-wideband RFID technology to get
the FCC green light for commercial use, Ubisense is looking at applications as
disparate as combat training and corporate office design.
Ultrawideband (UWB) Communications and Networking Symposium calls for
papers by February 15, 2005. Wirelesscom 2005 will be held June 13-16, 2005 in
Maui, Hawaii. Sponsored by IEEE, Wirelesscom is "The World's Premier
International Conference on Wireless Networks, Communications, and Mobile Computing".
For more information, see the
Call for Papers and the
general conference website.
Alereon Lays Claims To UWB Wireless Spec.
Wireless broadband semiconductor house Alereon says it completed the industry's first
over-the-air demonstration of 480 Mb/s and 320 Mb/s transmissions that meet the recently
released Multi-Band OFDM Alliance (MBOA) ultra-wideband (UWB) specification. The company
also says it took honors as the first company to demonstrate the mandatory 55 Mb/s-to-200
Mb/s data rates of the MBOA UWB specification.
Study sees trouble for UWB, By Mobile Pipeline News, CommsDesign.com, Nov 08, 2004.
A lack of standards and high price are threatening to make a bust of ultra-wideband (UWB)
wireless technology, according to an ABI Research study released November 8.
Dave Gorman has a problem. He has been given a large advance by a publisher to
write a novel and just cannot find it within himself to put pen to paper.
Instead he becomes engrossed in extreme googlewhacking. Dave Gorman's
Googlewhack! Adventure, published by Overlook Press on September 15, 2004,
is the very personal and occasionally hilarious chronicle of his dilemma.
For those who are in the dark about googlewhacking, here is an explanation.
Google is the premier web search tool. It indexes billions of web pages and
gives nearly instantaneous result when querying a word. It has become so
indispensable to us webaddicts that searching using Google has become a verb: to google.
Often, googling any given word will turn up millions of pages
that contain that word. Even unusual words will result in multiple thousands of hits.
For example, I googled "kumquats" and found 76,900 pages, and
"pentode" yielded 38,200. A googlewhack occurs when you find a combination
of two words that only exist on one page in all of googledom. These two words must be
English words (for English googlewhacking) that appear in
dictionary.com. There is just a single Google indexed page that contains both the words 'Kumquat'
and 'Pentode.' This page isn't a list of random or ordered words, just a nice readable page with
text on it, so it fully qualifies as a googlewhack.
For more information and a fuller explanation of the rules of this strange game, see our
Googlewhacking page.
But back to the book. Dave Gorman started googlewhacking to avoid thinking about his problems,
and before he knew it he was deep into a challenge from another David Gorman (who he located by,
of course, googleing his own name).
He (Dave Gorman, NOT David Gorman) would form a chain of googlewhacks by meeting the authors
of pages that contain the 'whacks and having them supply him with two 'whacks of their own.
Dave would then go visit the authors of the new 'whacks and so on. This chain had to be
ten steps deep and be completed by Dave's 32 birthday. This gave him just slightly more than
two months and meant that he would get tons of frequent flyer miles!
Although he is an international award-winning comedian, I had never heard of Dave Gorman
before the review copy of this book showed up in our mailbox. After reading the book, I
now feel as though I am on very personal terms with him, for better or worse! He is
brutally honest in describing his mood swings as the likely success of his quest wavers.
The descriptions of the personalities of the 'whackers leaves me feeling like I know them too.
The book was a little slow to get into, but by the midpoint I knew enough about our intrepid
English adventurer that I was genuinely anxious to know where the next set of 'whacks would
take him.
Did he make it? Well, that would be giving it away, wouldn't it? I can just say that I now
know that Dave is a stand-up comedian and is presently performing a live version of this book
in an Off-Broadway production. How do I know this? I googled it, of course!
For more information or to purchase a copy of this bestseller in the U.K., go to one of the links below:
Teena Rose is a certified and published resume writer
with Resume to Referral and author
of "Rèsumè Designs & Job-search Strategies for College Grads"
published by CareerEpublications in September 2003/
One of the biggest mistakes that individuals make in their
careers is to go aimlessly through school or work in an
entry-level position with no clear direction (goals). They wait
until the homestretch - graduation, layoff, or departure - before
taking a stab at other opportunities. Finding a well-paying job
or locating opportunities for advancement shouldn't be treated as
an afterthought, rather one that has been planned and prepared
for months or years.
Preparation, preparation, and more preparation! Imagine signing
up for a marathon and waiting until the day prior to begin
preparing for the race. Obviously, you're not ready because of
lack of training, you didn't seek the assistance of a coach or
mentor, and you didn't assess the resources you would need on the
day of the race. Without proper preparation, what are your
chances of completing the race?
Like any serious step you'll take in life, you must first
determine the number of baby steps needed to get from one spot to
the next. In other words, where are you headed and how will you
get there? Outline every obstacle or challenge that will hinder
your progress of taking these steps. Each small step (short-term
goal) will take you closer to satisfying the big steps, known as
long-term career goals.
First, take a good look at the types of positions you've held to
date along with your college major. Ask yourself, do I like
where I'm at and where do I see myself in 5 years? Don't be
ashamed if you're not sure. Visit your favorite job bank, type
in keywords for your intended career field, and examine those
positions to determine if any meet your satisfaction.
Second, write down job and career goals (preferably 6 months
before graduating or the start of your intended job search). Job
goals pertain to the position you currently hold now, whereas,
career goals are the 'big picture' (e.g. career change in less
than two years or targeting a six-figure salary). Research 2 or 3
positions that you would love to obtain TODAY along with those
you're striving for in a couple of years.
Third, prepare yourself, your credentials, and your résumé based
on your predetermined career opportunities and goals. Prepare to
go back to college, join business groups, serve on committees, or
alter your résumé to encompass all (or any) of these.
In a career journal, make notations of the positions that
interest you along with the skills required for each. Add other
entries pertaining to outstanding credentials, and miscellaneous
obstacles in the order that'll need to be completed, with
resolutions and proposed dates of completion.
The object is to not stand still. Navigate your future by
performing a self-assessment that will get you from a to z in
your career. Jay Block says it best in the book, The End of the
Job Search, Mastering the Art of Career Design: "Defining your
career aspirations is an essential step in the process of
transforming abstract thoughts into tangible realities.
Everything ever accomplished by man or woman first started as a
thought." I challenge you to assess yourself and create a master
plan. It's ONLY your career!
