Space is a really tough environment. Electronic parts must suffer massive shock and vibration during launch and often see wide temperature swings as satellites are heated by the sun then slip behind the earth into very cold outer space. Most space parts must tolerate a vacuum and heat must be managed carefully. Radiation hardening is critical as a spacecraft is bombarded by a merciless sea of high-energy particles. Parts must be clean and outgassing limited, to ensure that camera lenses are not clouded and there is little tolerance for repairs. Designing and building parts for space requires tenacity and a commitment to process… from managing ESD, testing, and training to handling analyses correctly and efficiently.

Procurement specifications for space are usually written for the requirement at hand. A scientific mission with a tiny budget will rely on the expertise of the manufacturer to assist in defining the technical details of the part and testing. A commercial satellite will have more detailed specification often defined at the satellite level, rather than for the particular assembly required as part of the satellite. Costs can mount as program managers sift through technical data and handle all contingencies. And missing a deadline is not an option.

Standardizing specification around existing MIL standards and specifying hardware already designed for space can reduce costs, improve lead times and overall, improve the quality of life. A paper that I delivered at PTTI in Reston, VA provides more details on the benefits of this approach. Read Paper

In 2008 and 2009, it was evident that debt-free companies with strong cash flow would perform well while overly leveraged companies would face severe consequences. Our belief was that companies with strong manufacturing capabilities and a commitment to technological innovation would eventually benefit from the downturn since. At that time, Marki Microwave invested heavily in developing new product lines, both as a way of diversifying our revenue streams, and as a way of increasing our technological acumen. Our R&D efforts during the global Recession proved well advised because we have enjoyed more than 100% year-over-year growth in all three of our new product lines including Couplers, Filters and Power Dividers. We actually experienced an excellent 2010 on account of these new product lines, and the continued adoption of our high performance T3 mixer line. By many accounts, we are not alone in believing that the RF and Microwave industry is very active currently, and that there are many opportunities for many exciting technologies in 2011. We believe that small  companies with experience and specialized expertise will continue to prosper in an industry thirsty for technological advances. Let’s put it this way: I just finished writing Marki’s R&D timeline for 2011, and I can’t wait to announce the kinds of new gadgets and gizmos we have on the fire.

2.    How have social networking websites impacted your business? Do you believe that online communities like LinkedIn, Twitter and Facebook have a meaningful place in the RF/Microwave industry?

For an industry rife with scientific experts and technological sophistication, we are incredibly old-fashioned. Compared to other industries, we are one of the most conservative, and this translates into being slow adopters of new technology. For example, our company still sells a mixer my father designed in 1975, simply because the customer refuses to adopt the newer, better version. I understand that “if it ain’t broke, don’t fix it”, but sometimes change is good.

Since the day I began working at Marki, I have had the strong opinion that the internet is the single most important ally for our small business. For this reason, Marki cut back significantly on print advertising and the other “traditional” marketing tools. It is not that they don’t work, we simply believe that Marketing dollars and time are more efficiently spent on tools like Adwords and, obviously, online blogs. If I had the budget to advertise on every other page in the Journal I would, but not all us have the privilege. Therefore, Marki Microwave openly embraces all the social networking (marketing) forums, and we work hard to make this participation meaningful for our customers.

Make no mistake, though, the industry as a whole has been slow to adopt forums like Twitter and Facebook and the jury is still out on how the average RF engineer will use these avenues going forward. I would argue, however, that we are at the beginning of a very long adoption curve, so this will be a multi-year trend. To use a (poor) photonics analogy, the process will look less like stimulated emission of a photon and more like spontaneous emission of a photon—we can’t really control when, where or at what wavelength the photon will be emitted, we just know that over some measurable amount of time, the photon will eventually emit (our LED friends an CREE will appreciate that one). Look at the way the internet changed the way RF engineers design: vendors used to have pay sales reps in all the key geographic locations to, literally, walk into a customer’s building to hand them a (gasp!) printed catalog. Now, the customer goes online to find the most up to date information and has the option to request a quote within seconds. Advertising has followed a similar path, and it is no surprise that all of our trade journals are skinnier than they used to be. Don’t misunderstand, I still greatly enjoy trade journals and read them religiously, I am simply stating that we have more options today that go far beyond traditional print. We no longer have to publish papers in journals or in our printed catalogs, we simply post them online for all to freely download. And do you know how we announce these new papers and application notes to the industry? By posting about them on the Marki Microwave Twitter, Facebook, and blog websites. I encourage any and all of our customers, partners and readers to join us on the websites. This industry will look significantly different in 5 years, and Twitter, Facebook, LinkedIn and (possibly) RFblogger will have something to do with it.

3.    Many have argued that there is a shortage of RF/Microwave engineers. How do you see this problem unfolding in the short and long term, both as it pertains to your own business, and the industry as a whole?

The shortage of good RF engineers is a major problem. Forget about the RF industry, the shortage of American engineers is a major problem. Out of the 20 or so close friends I graduated with in undergrad in 2002, only 3 were engineers. Of those 3, I am the only practicing engineer. The other two jumped ship and went the MBA route. It seems that the engineering discipline is either too boring, too hard, or too unprofitable for most Americans.   I think it is all of the above.

In the near term, I doubt we will see significant fallout from this shortage on an industry or national level. The larger problem involves what will happen when all the engineers from my father’s generation retire in the coming 5 to 10 years. My father and  I talk to many companies, and we hear constantly that many larger RF/Microwave companies are forced to reconnect with former, retired employees in order to finish projects because the expertise is not passed on to the younger generation. Eventually, these RF wizards will not be around to bail us out and the entire industry will suffer as a result. It is essential that the companies in our industry pass on this engineering expertise to the next generation of engineers. At Marki Microwave, we have a clear chain of succession, and we pride ourselves of passing on all the hard-fought knowledge to our engineers. However, there are other, especially small, companies in the industry who are in danger of losing their technological edge if the founder’s expertise is not passed on. I hope that engineers in my generation surface in the next decade that can carry the torch of our predecessors. Currently, I am looking to hire such people, and I can testify that it is a difficult process.

4.    As a small business and an entrepreneur, what advice would you give to an RF/Microwave engineer looking to start a company?

Know what you are good at, know what you are not good at. Avoid the tendency of over-engineering your first generation of products. Give your customers what they want, not what you think they want. Don’t assume an idea is bad just because you think it is obvious. Don’t assume and idea is good just because it is devilishly complicated. Be patient, it usually takes 1 to 2 years before a new product becomes adopted by the industry….I could go on and on….

5.    What do you perceive as the hottest markets for the RF industry for the coming year?

If we are to use the stock market as a predictive tool, then the fiber optics market is set to explode in 2011. Granted, we have been waiting for this to happen for over a decade, but the smart phone/streaming Netflix era has consumed the available bandwidth, and people who make fiber optic hardware are finally going to make some money because of this. (Go look at JDSU or Finisar stock if you don’t believe me). I happen to agree with this premise, but I also believe that such speculation is always tenuous: the technical challenges tend to require state-of-the-art technology, but the customers demand commodity prices…that is a recipe for disaster if you actually want to make a profit. I have personally witnessed millions in venture capital be wasted because of these paradoxical requirements.

From a communication theory perspective, we are in the process of improving the spectral efficiency of optical fiber. Legacy systems usually use 10 Gb/s on-off keying to transmit data. This is Stone-Age technology compared to what we use in cell phones. Using the wireless industry as inspiration, photonics companies began solving the spectral efficiency problem. From what I understand, the price points and bandwidth demand are now justifying the network upgrades. Food for thought: I was told by a very reliable source that the pain is going to get worse (in terms of the network bandwidth shortage). If one looks at the exponential increase in required network bandwidth over the next decade and compares it to the average power consumption of running the servers, one finds that within the next decade or so, the fiber optic network will consume more power than the United States can produce, given current energy grid capacity projections. In other words, the US energy grid will not be able to support the optical network power consumption per bit. If I were a betting man, I’d say it is time to invest in technologies that will significantly lower the energy/bit in optical networking hardware, it is the only reasonable options since the energy grid capacity cannot be improved at a reasonable pace. If history is a guide, that means that the solution will come out of the electronics domain, not the optics domain. Take it from a former optics guy; electronics always wins.

So you’re thinking about getting a Masters of Ph.D. in engineering or science? Well, if you’re like I was, then you have heard a lot of rumors about what the whole process is about, and what you can expect out of it. In my experience, the advice floating through the halls of undergraduate universities and companies can be suspect at best, and misleading at worst. Having gone through the graduate school process recently, I would like to offer a little clarity on this oft-deliberated question. Today we are going to talk about grad school: Fact or Fiction.

The Ph.D. is just a longer version of a Masters—Fiction

Both are important, but for different reasons. In my view, the Masters degree acts as a form of continuing education for the undergraduate degree. Basically, a Masters builds on the foundation of the generalized undergrad education to give a deeper level of understanding for more current topics. The Ph.D. involves the coursework aspects of the Masters, but eventually sends the student onto a metaphorical “intellectual island” to fend for themselves in the grueling world of academic research. In order the get a Ph.D., the student is expected to make new scientific contributions to the field and publish papers in peer-reviewed journals/conferences. The Masters student can do this, but is not usually required.

Graduate courses are much more interesting than undergrad courses—Fact

Undergrad courses are boring, the problem sets are excruciating, and the grading is cut-throat. I believe this pain is intended so as to (high pass) filter the weaker students. The good news is that graduate courses are more interesting because you learn more the most modern topics and many courses are taught by the experts who are actually pushing the field to new heights—this latter fact implies that the professors tend to enjoy teaching the higher level courses, which always makes for better lectures.

Graduate courses are very difficult—Fiction

In my experience, exams and grading are much more difficult in undergraduate courses. Professors tend to treat the graduate students much more benevolently.

The Ph.D. is a waste of time—Fiction

Surprisingly, many people believe that a Ph.D. is not worth the time expense. Arguments often include the “opportunity cost” of the Ph.D.—this is the income “lost” by not working in a “real” job during those 4 or 5 years, the fact that you work on a single problem for so long and become too narrowly focuses, and the fact that you do not gain real world experience. For me, these are all red herring arguments.

First, most science Ph.D. programs pay their students monthly stipends for the work, or for TA-ing. It is not a lot of money, but it is a living wage, and not egregiously lower than an entry-level engineer with a BS. Most people in their twenties don’t have a high cost a living, anyway.

Second, while it is true that a Ph.D. covers a narrow list of topics, the breadth of knowledge required is immense. For every paper you write in grad school, I’d estimate you read hundreds of reference papers just to appreciate the “shoulders of the giants” you are standing on. After 5 years of grad school, I would guess I had read literally thousands of IEEE and OSA papers. To me, that is the opposite of being narrowly focused.

Finally, the argument that the Ph.D. process is an incubator that does not teach real world experience is horribly misled. Have you ever witnessed the political cattiness of rival professors? If not, I assure you it would make for some amazing reality TV. Just as any corporate job requires you to be aware of the politics of the office, and the inter-personal relationships of the people in your team, the Ph.D. requires you to understand that the academic process, and research in general, is a dog-eat-dog world. Make no mistake, when it comes to University level research, careers and millions of dollars are at stake, and any Ph.D. candidate can testify to this fact…tell me that’s not “real world”.

When you graduate with a Ph.D., people will respect you more—Fiction

I often tell people, “the only people who call me Dr. Marki are the ones who don’t know me.” Translation: your friends, family and colleagues couldn’t care less about the Ph.D.—I think that is a GOOD thing.

You can choose a school with a great program, or you can choose where you want to live, but not both—Mostly Fact

When I applied to grad school, I had one criterion: get back to California. Essentially, I spammed every California-based EE/ECE program I could find. I lucked out with UCSD, because San Diego is the greatest city in the country—I defy you to prove otherwise. Nevertheless, my optics professors at Duke kept telling me about the University of Rochester, because the school is well known for groundbreaking optics research. You know what I did? Ignored them. This west coast boy can’t take those upstate winters. Being from California, I was lucky because we have so many great engineering programs from which to choose, but in general, that is the exception to the rule. It is very difficult decide where you want to live, and then successfully matriculate to the perfect graduate program. You get to pick program, or location, but not both.

Besides your spouse, your Thesis Advisor is the most important personal relationship you will ever choose—Fact

This was great advice given to me by my own thesis advisor during orientation. Your thesis advisor is something akin to an adopted parent who can fire you. Choose wisely.

Your thesis topic does not matter, only that you finish—Fiction

Many people believe that your thesis topic does not matter because you will never actually work in that field after you graduate. I would be an example of one of those people, my thesis has little to do with RF/microwave engineering. However, I have come to find that the people who actually work in a field similar to their thesis often have an advantage, especially when they start companies. Jason Breitbarth at Holzworth is a prime example. Jason did his thesis work in phase noise at UC Boulder and now owns a company building low phase noise equipment. This is not surprising, building an engineering company requires unique expertise and insight that can be productized, the Ph.D. process helps you acquire such knowledge and this can help tremendously when creating new companies.

The Ivory Tower is much different from the real world—Fact

Yes, grad school teaches you real world experiences, but it is not the real world. In the real world, people don’t care nearly as much about science. This fact was very hard for me to accept when I first stepped out of UCSD and into the halls of Marki Microwave. When you are doing your Masters or Ph.D., everyone clearly cares about doing good work, exploring new areas of science or engineering, and competing for the admiration of their colleagues. In the real world, engineering or scientific achievements are often tempered by budgets, due dates, supply chain issues, economic uncertainty and office malaise. This is the inevitable trade-off when weighing whether to go to grad school: you can choose “scientific utopia” for a few years at the expense of lower pay and fierce competition, or you can choose higher pay and higher quality of life but having to accept that your contributions will often be muted by factors well beyond your control, but not both. For me, experiencing the Ivory Tower for a few years was well worth this trade.

Your thesis committee will not read your thesis—Fact

Shocking, but true! When you defend your thesis, at least one committee member will be late (they are on “professor time”, after all), at least one committee member will be checking his email, and at least one committee member will be cracking open your dissertation for the very first time. I am not kidding. The fact is that by the time you publish 3 or 4 papers in your field, you know more about the area that any of your committee members, so their job isn’t to check your work line by line, but to ensure that the work was done with a high degree scientific integrity. Good professors gain a profound intuition into the scientific process; its almost like they can smell good or bad work, without actually knowing the details.

The only people that will ever read your thesis are in your lab group—Fact

Your mom or spouse might give it a go, but they won’t get past the first few pages (unless they have a degree in your field). My thesis is posted on the Marki Microwave website, and I strongly doubt anyone has read it in firm detail.

You will sink, or you will swim—Fact

Yep.

Now that the year is winding down and we are feverishly completing our final shipments for 2010, it is time to look back and see what we accomplished over the last 300+ days. By most accounts, 2010 seems to have been a very good year for the RF/microwave industry. While it is true that Marki Microwave is a small player in a very big and diverse industry, I feel that my particular vantage point gives me some insight into what we are seeing both economically and technologically. I want to talk about some of the trends I have been seeing, and how Marki has been able to take advantage of a few of them. Since Marki is a private company, this is just about as close to an investor conference call as it gets for us, but I would imagine that much of what I say will be true for the big boys in the industry like Hittite and Triquint and Avago.

Trends

Broadband, broadband, broadband

I am obsessed with bandwidth, and I’m glad to see that the industry is too. Since Marki specializes in broadband components such as mixers, couplers and power dividers, I am always excited when a customer comes along and needs a power divider from 1 to 65 GHz, or a mixer from 10 MHz to 12 GHz (T3-12) . Interestingly, we have witnessed a very strong push this year from customers with very large bandwidth requirements. I believe this is coming from several trends. First, RF designers are finding that it is cheaper (and more elegant) to design a system with a few expensive, very broadband components than a lot of cheap, narrowband components. Many of our customers have gravitated towards our T3 mixers for this reason; they find that they can avoid investing in extra mixers, switches and amplifiers by using a single mixer that can cover the whole band and can be used with a flexible LO drive. Yes, the T3 might be 5x the cost, but they have purchased 10x less parts, and this translates to quicker design turn around and a lower risk of failure during board integration. This insatiable need for bandwidth is strongest in the test equipment and surveillance area and if anything, the demand is increasing. Another trend pushing the need for bandwidth is flexibility. In my opinion, the wireless area is over-populated with commodity components. While this is good for making your iPhone inexpensive, it is generally bad for military-type folks who need to communicate far away from the overpopulated low-GHz bands. I went to MilCom in San Jose a few months ago, and the JTRS radio was the big hit. One of the key benefits of this radio is its ability to work over a multitude of bands with untold numbers of modulation formats. Simple commercial components designed for the wireless industry do not satisfy such requirements, in part because they are designed with cost in mind, not flexibility in performance and application. Many customers call me nowadays with these flexible bandwidth requirements in mind, I expect it to continue into 2011.

High power and high linearity

If you are like me, you are sick of hearing about high power amplifiers, or PA’s for those who have been living under a rock. I estimate is that there are about 3,649 companies marketing themselves as PA experts, and apparently there is enough business to go around. OK, I am exaggerating, but PA’s seem to be the soup-du-jour (that’s the soup of the day for you ‘Dumb and Dumber’ fans). As a general trend, however, we do see that people are very concerned with the science of high power RF signals, and the components that can perform well at these powers. For Marki, we have enjoyed this push in the form of our high linearity mixers, yep, the T3’s again. I have written an app note about the T3’s, these mixers are amazing and offer the high IP3 and 1 dB compression in the industry. I am also seeing many inquiries for higher power couplers and combiner/splitters. I have put this on the To Do list for 2011.Why the need for more power and more linearity? There is no single answer to this question. In truth, the push for power and linearity stems from both commercial and military applications, alike. The “sexiness” of PA’s is explained by the fact that people want to transmit more power more efficiently for less cost. Hence, you see all those articles in the journals about GaN, GaAs, Triquint, Cree, PAE, etc. The quest for linearity stems from the trend of employing complex modulation formats to push more data down the pipe and the need for higher dynamic range systems. Components that can achieve better linearity performance through metrics like 1 dB compression, spurious response, and two-tone intercept all cater to these modern systems.

Surface mount to higher frequencies

There is a saying in the field, “the money’s in the packaging”. The modern incarnation of this trend is that components makers are being pressed more and more to offer higher frequency surface mount packages for their products. At Marki, we are unique in the fact that we are the only hybrid mixer maker that offers surface mount packaging beyond a few GHz. As opposed to GaAs mixers and LTCC mixers, hybrid mixers are challenging to make surface mount because they require suspended substrates that must float physically far away from ground. This poses a challenge for the packaging because the signal must therefore travel a long distance vertically before entering the circuitry. Marki solved this problem by building a 50 Ohm transmission line directly into the side of the metal carrier. We call this our ‘EZ’ package and is offered for mixers up to about 30 GHz. Amazingly, I have been getting calls over the past year where people want to go to even higher surface mount frequencies beyond 10 or 20 GHz. This trend is justified because surface mount assemblies are lighter and smaller (and cheaper if done correctly), but the designers still have many challenges to overcome. For one thing, surface mount assemblies to 40 GHz, for example, require an expert-level understanding of microwave packaging science and mechanical layout/design. In other words, even if the manufacturer can provide the components to 40 GHz, the system level assembly is still going to be a big headache. The mistake I have witnessed is when people underestimate the difficulty in building surface mount assemblies above 20 GHz or so; it is full of pitfalls and requires an experienced hand. Nevertheless, the trend continues, and I don’t imagine it is going to fade.

Thank you Christopher Marki for the wonderful engineering and personal insights that you shared in the Microwave Journal. We read them, passed them around, and felt at one with you as an engineer in a small business who cares about the technology  (the stuff) and your family, co-workers and customers (the people).

At Wenzel Associates we are a close group of engineers, technologists and manufacturers, people who also love the stuff and the people. We make very low noise oscillators, frequency based systems and synthesizer to about 16 GHz. There are lots of custom modules shipped from our Austin, Texas facility, some in complicated nickel-plated aluminum boxes with Spira shields to reduce cross-coupled spurs, some that slide into rugged racks mounted in a fighter jet or mount on the cold plate of a satellite ranging system.

We hope to contribute bits of useful information to RFblogger, life’s lessons perhaps, things relevant to the RF field. I am Liz Ronchetti, President and co-founder of Wenzel Associates with my husband, Charles Wenzel, our CEO and the brilliant one in the family. John Richardson is our Head of Engineering at Wenzel and I bet we will see posts from him in the future. My BSEE degree is from Worcester Polytechnic Institute in frosty Worcester Massachusetts and I am grateful to be writing from warm and sunny Austin, Texas.

So what’s all this about 217Plus?

We recently ran into a source control drawing from a prime contractor that called out 217Plus, rather than MIL-HDBK-217F for its MTBF calculation. After a bit of research and a call to a very nice QA engineer at Lockheed who forwarded me to another, here is what I learned.

“Everyone knows that MIL-HDBK-217F is outdated,” having last been updated in 1995. Lockheed (among others) reviewed suppliers, looked at processes and histories and decided if an improved number was appropriate, sometimes for a single part, sometimes for a complete line.  They applied a methodology on the numbers, making judgments and surveys and supplementing them with more data, always applying the same criteria. They sent their methodology to the Navy to verify that they were good with it. The Navy saw that there was a mismatch with what happens in the field and the 217F predictions, and that the new predictions gave results that were actually closer to what happens. In many of cases this approach was preferred by the Navy because it was more accurate and also kept needless costs down.

MIL-HDBK-217F Methodology

MIL-HDBK-217F defines the “failure rate” by calculating a rate for each subcomponent. The rate is assigned by part type. For example, the formulas needed to calculate failure rate for a ceramic capacitor (Fixed, ceramic, general purpose CK, CKR) differ from the formulas for an FET (Transistor, High Frequency, GaAs FET). Formulas for each part type’s specific reliability effects are detailed and multiplied together for a final “Failures/10e6 Hours”. In the case of the ceramic capacitors the factors are:

λ_b base failure rate => ambient and max rated temperature, stress (ratio of operating to rated voltage)
π_CV capacitance  factor  => uses capacitance in pF
π_Q quality factor => part quality type , S, R, …, MIL-C-11015 non-established reliability, and lower
π_E environment factor => ground based GB, airborne inhabited cargo AIC, etc.

This modeling system, by its own admission, is limited. The information in a released standard can only be as up to date as the data at time of publication. The writers recognize that “Electronic technology is noted for its dynamic nature”, and write that reliability will certainly vary by the differences in system application, operational scenarios and even in the definition of failure.

Something better

It seems that, from lots of collected data and analysis, new standards have evolved, probably not as suddenly or as easily as it seems. Some companies, in conjunction with the DOD and the Reliability Information Analysis Center (RIAC), have built software around these standards. PRISM® software, originally released in 1999, is available through System Reliability Center (SRC). In 2006 the upgrade 217Plus was released by the RIAC and is available through SRC. Relex, from Parametric Technology Corporation, is the software that we use for our MTBF calculations, and it also supports PRISM® and the 217Plus upgrade. There may be other programs available.

Eventually, MIL-HDBK-217 will be updated to Rev G; it has had an initial release for review and comments, but is still a work in progress.

Why is this important

This is significant to RF designers and manufacturers, any of us who have scoured data sheets and poured through websites looking for a good MIL-style varactor. MIL parts are expensive. They are less available than they were and we are finding more MIL parts have become obsolete. What were our favorite parts may be no more because better more reliable parts are available and have replaced them. Many of these new parts are characterized in 217Plus.

So new designs can be cheaper and have a shorter development time; we are all grateful for this. Now, new reliability information is readily available, accessible and easy to use. The creation of 217Plus also suggests that we are getting better at producing high quality high reliability parts as a group. This means safer air travel, better radar systems and lower cost mobile radios.

Of course, we will use caution in applying 217Plus. More research is needed to learn the applicability of the new data and find out who is currently using it. There may be cases were the new numbers are not approved, such as in space work, or for some mission critical designs that were qualified a long time ago and any changes means the addition of risk. But it is very welcome.

Liz Ronchetti
Wenzel Associates, Inc.

To introduce myself, I’m the primary founder of Holzworth Instrumentation. I have the usual years of background at other companies, too many degrees and generally overly educated for my own good. What all this means is that I’ve learned some very valuable lessons – some of the most useful things related to circuits, I’d learned in my Junior year while completing my BSEE. These circuit design techniques and linear regulator design are the most useful skills (I believe) an RF engineer can have.

At my first job out of school, all of my focus was on microwave design - assuming that it had to be the good stuff. Time and time again, the RF only took half the time while the other half was designing the low noise circuitry with Op-amps and BJTs; which are really what make the RF work after all. I was fortunate to have the remaining professor at Oregon State without a PhD, teach me data acquisition. He did not teach from text books – he was the text book. I remember him laughing at us during our Senior year because none of us could really use a BJT very well. We laughed too, mainly because he was right. I learned more useful design skills from that class than most of my post-graduate classes.

Now fast forward more than a few gray hairs, we were designing our very first synthesizer – the HS1001A. Care to guess what circuit that took the most design time? Power supply. Not the AC-DC kind, but the standard old linear regulators. What I found was that even the ‘low noise’ linear regulator ICs weren’t very low noise. By this time in my career I’d had an intensive phase noise background where everything was running off batteries to maintain extremely low noise levels. But how to make a linear regulator that is close to the noise of a battery? Was it possible to take whatever a customer applied as a source voltage and make all the noise disappear to the level of a battery?

Enter the noise stuff. Everyone remembers Boltzmann’s constant, or at least hearing about it. And then this ’Johnson noise’ stuff, and somewhere during that Junior year you learned that resistors make Johnson noise (white noise) depending on the resistance value of the resistor in the form of noise = sqrt(kTBR). I’ll keep equations to a minimum as Steven Hawking correctly pointed out that the number of readers is inversely proportional to the number of equations. That notedequation also relates that the bandwidth you look at is as important as the temperature. The temperature is in Kelvin and for practical
purposes, fairly constant near room temp. The phase noise guys really prefer everything normalized to a 1Hz bandwidth, so that the ‘B’ variable goes away. The equivalent resistance (‘R’) is really what
causes noise in our system.

What level of noise? A 50ohm resistor (or system) has around 0.9nV/rt(Hz) of noise. A 1k resistor has ~4nV/rt(Hz) of noise and a 100k resistor has ~40nV/rt(Hz) of noise. When you look in terms of a log
scale (using 20log because of voltage) you can see a 1k resistor has 12dB more noise than a 50ohm resistor and 100k has 20dB more than the 1k. These are huge in terms of microwave. I bring this up because these are the numbers you’ll see on those linear regulator and op-amp spec sheets you might use to build your own linear regulator.

You’re designing RF now – why would all this matter? Well, let’s take an amplifier as an example example, an LO amplifier that is pretty critical to system performance, maybe you’re driving a mixer with it. You want to drive it into p1dB compression to suppress AM noise, a clever trick thinking you’re getting rid of AM noise, but are you? Ask now, what is the AM-PM conversion of this amp? Most engineers have never even measured it. It’s pretty simple. Take the amp and put it on a network analyzer, measure the S21 phase at your nominal power supply, now drop or raise the power supply a volt (or something) and measure it again - it’s different right? This is AM-PM conversion. Any noise on your supply will be converted into phase noise in a nice neat step. And once it’s there, you can’t get rid of it.

Now say you hand off the RF amp’s linear regulator design to the ‘new engineer’, a process I find baffling. Nothing against the new engineer, but we typically don’t learn good regulator design in school. He/she uses an average linear regulator IC that has 100nV/rt(Hz) of noise on it (40dB above 50ohm noise), job done. When compressing an amplifier, the voltage swings almost entirely across the I-V curve, causing fairly large changes in phase. This is why time domain guys use differential amps – they don’t suffer from this, but they have other signal to noise problems that make them not suitable for phase noise work. Say the phase moves 20degrees over a volt change, a ‘volts per radian’ of 0.35 exists, which is the inverse of a mixer as a phase detector. Now multiply by the voltage noise of 100nV/rt(Hz) and take the 20log of it. You get a phase deviation of -150dBc/rt(Hz) with 100nV of supply noise. This is what
you’ll measure for ‘phase noise’ at the output of your amplifier that is probably capable of much better. Worse, your linear regulator is probably much worse than this at 1kHz offsets compared to 100kHz offsets.

So now you’ve just spent all this time on choosing the best mixer, amplifier, oscillator and you degraded the entire system with a $0.50 linear regulator. How good does the regulator need to be? Well that
depends on your desired system performance level, as described above. What does Holzworth strive for? The linear regulators that we design discreetly exhibit between 1nV/rt(Hz) and 3nV/rt(Hz) depending on the application and usually > 100dB rejection from input to regulated output.

How do you go about finding out about linear regulator design? Take a step back, do some web searching on low noise regulators. The audio guys are the ones that really do a good job. Start there. Next to phase noise work, audio has the most use for a low noise regulator.

In the next blog, I’ll discuss how to measure the voltage noise.

Who’s better: Tom Brady or Steve

People often ask me how many patents Marki Microwave owns. The answer: zero. “What? But you’re a technology company, how can this be? Aren’t you worried that someone is going to steal your idea?” Well, not really, and I will try to explain the logic behind this position. Some will read this and disagree, I have no doubt. I actually think patents do have important benefits given the right set of circumstances, but I think for small tech companies like Marki Microwave, patents do not provide as many benefits as is often assumed. I believe it is false to assume that a good idea should always be patented, here’s why…

1. Patents create a false sense of security. In general, I’m opposed to people trying to lay claim to scientific discoveries and innovation. I know many engineers who spend most of there time writing patents, re-writing patents, and conceiving of ways to get around other’s patents. To me, this is a sub-optimal strategy for success. There is a difference between “patent competition” and “technological competition”. Patent competition is the act of performing a metaphorical patent land-grab, this is not necessarily useful for the greater good of society. Technological competition, however, is supremely good for society and the economy. Most people are motivated by adversity. Therefore, when you have a technological competitor, regardless of whether they own a patent or not, you are forced to innovate beyond your current means. The patent owner, however, might be tempted to believe he is safe from copy-cat technologies. I believe this complacency is a very dangerous mindset to have in a competitive marketplace. You can’t control whether your competitor will leap-frog your technology and render your patent useless. No technology company can survive forever without constantly improving their “wheel”, a patent does not provide us reprieve from this fundamental Truth.

2. Trade secrets are more important than patents. I love when my competition writes patents because they give me insights into the thought process of the inventor. I have read several patents that were so novel in their approach that they actually triggered new ideas for me, which I subsequently used for my own applications. Did I violate the patent? No. In fact, my idea was for something totally different. However, the patent described the technical details in such a way that served as a sort of creative inspiration. Had the inventor never written the patent, I doubt I would have come up with the same idea in such a short amount of time. I believe that trade secrets are more powerful than patents because they foster many more questions than answers for the competition. If you are a small tech firm, it is perhaps more valuable to develop your “secret sauce” in private and let your competitors try to reverse engineer your product later. In my area of hardware, the money is in the packaging details. In other words, I can give a Marki mixer to a competitor, but they still might not be able to copy it due to the fabrication complexity and assembly subtleties. However, if I write the patent and describe the function and detailed embodiment of the design, then they are more likely to understand the meaning behind my design choices. This is dangerous, and the single biggest reason Marki does not write patents for mixers.

3. Would you really sue over patent infringement? The best argument I have ever heard for why a small company should own a patent is that it gives you a legal precedence to continue to sell your product. In other words, you don’t patent something so you can sue someone when they violate it, you patent something so they can’t sue you when they try to steal your idea by patenting it themselves. It is backwards logic, but it makes sense. Moreover, how many small companies have the financial power to litigate potential patent infringement? Not many. Even the most air-tight patent can be circumvented with a few clever strokes of the pen, or an equally intimidating legal department.

4. A patent is NOT a product. I know many brilliant engineers who believe that if they patent all their ideas, that they will eventually become rich. In some sense, they treat their patents like lottery tickets; if they hold enough tickets, eventually their number will be called. Ultimately, the end game is to sell their ideas and corresponding IP for a huge lump sum and retire happy. I have found that many smart scientists use this strategy when they form start-up companies. Many of the tech start-ups I’ve dealt with in my career have a business plan that looks something like this: have a great idea, acquire funding either through venture capital or DOD, develop an IP portfolio, sell company to highest bidder and cash out. In other words, the product of the company is…the company! I don’t believe this is a good or bad thing, I simply believe that it is strategy with a low probability of success. Maybe I’m old fashioned, but a company makes money by providing goods and services to their customers, not by acquiring IP that may or may not be useful some day. There is a reason that tech start-up companies are so risky, and I think worshipping patents as false products adds to this risk. Of course, there are many famous companies who have successfully made the transition from start-up to juggernaut, but this tends to be the exception, not the rule. We can’t all be Google or Intuitive Surgical, so should we all try to be?

Google is an interesting example actually. The most valuable asset in all of Google is their search algorithm, and specifically the relevance calculator. While it is true that the “PageRank” concept is a licensed patent from Stanford, the actual weighting of the various search factors are secret. Marketing people make entire careers out of trying to optimize websites to fit Google’s algorithm, but no one knows with absolute certainty how it determines rank…this is a fantastic trade secret indeed! If someone could figure out how to decrypt the Google search algorithm with quantitative accuracy, I suspect they would be rich beyond words, maybe I should write a patent…

Christopher F. Marki received his B.S.E.E. from Duke University in 2002 and his M.S.E.E. and Ph.D. from University of California, San Diego in 2004 and 2007, respectively. While in graduate school, Christopher studied high speed fiber optics and consulted for San Diego start-up Ziva Corporation. Following graduate school, Christopher decided to forego a life in Photonics and opted, instead, to work with his father at Marki Microwave and learn the “family business” of microwave mixers. While at Marki Microwave, Christopher has served as Director of Research and has been responsible for the design and commercialization of many of Marki’s fastest growing product lines including filters, couplers and power dividers. Dr. Marki has authored and co-authored numerous journal and conference publications and frequently serves as an IEEE reviewer forPhotonics Technology Letters and Journal of Lightwave Technology.

When people ask my advice about pursuing a career in Engineering, I tell them the following:

After the long and sometimes strenuous journey one takes in the product development cycle, the inevitable final stage can be the most challenging: the making of the datasheet.

As an engineer, I dislike making datasheets. I loathe the idea that I am required to summarize the macroscopic workings of my “babies” (i.e. new products) with bold, unforgiving numbers that can never fully represent the “inner beauty” of the product. For me, the datasheet is a wholly inadequate creature that almost always fails to capture the many nuances of the product. Seriously, am I expected to describe all the workings of my new products in a few tables and graphs in .pdf format? Unfortunately, yes. So it looks like I’ll just have to accept the truth and adapt accordingly.

Complaints aside, datasheets cannot be underestimated in their importance. When I put on my Marketing Hat (I wear many hats at Marki Microwave, it goes with the territory), I am forced to acknowledge that datasheets are the all-important first impression; they are the lens through which my company and product lines are initially judged. Therefore, we place much emphasis on making our datasheets as clean and precise as possible. Through my experiences with using other vendor’s datasheets and in creating my own, I have formed some opinions about the “correct” way of making, displaying, and using datasheets. I concede this is a subjective area, so I’ll try to be as objective as possible.

1. Minimum and Maximum specs are guarantees, Typical specs are not. For vendors, the delta between Min/Max and Typical is our breathing room. At Marki Microwave, we use typical specs to describe the average performance of the part across the band. Therefore, if the Conversion Loss of the mixer is 7 dB (typ.), then that is about what the measured value will be on most units, over most of the band. That doesn’t guarantee the number won’t be 7.5 dB near the band edge, just that the statistical average is close to 7 dB. Choosing Min/Max/Typ is not a perfect science, but honest vendors work extremely hard to identify these values as accurately as humanly possible, trust me. Moreover, most vendors will even do a few extra measurements for you, you just have to ask nicely. Remember, measurements = reality, datasheets = quasi-reality. (The caveat, of course, is that I am assuming the measurement is performed correctly, but that is a different topic for a different time).

2. Product tables are not datasheets. Some vendors do not make datasheets available on their websites, only product tables. These tables display key information (insertion loss, return loss, etc), but not in any detailed format that is quickly confirmed with included measurement data. As a designer looking for a product, I dislike product tables for two reasons: the numbers are too ambiguous, and they make me think the vendor is hiding something. When it comes to product performance, I like to see curves and graphs. For example, if an amp has 15 dB gain, I want to see how that gain changes with frequency. This information can be critical to my application. More importantly, when it comes to choosing parts for my designs, I tend to feel very skeptical of vendors that only provide me with tables of numbers and no actual measured plots—it makes me worry that the vendor is hiding some kind of flaw or glaring weakness. I have actually heard rumors that there exist companies, past and present, that “create” new products simply by adding new rows to their product tables without ever having built the widget. Such horror stories always leave me with a sense of caution when choosing my suppliers. From a marketing point of view, the solution is obvious: be as transparent as possible and provide as much information as possible. This will yield brand loyalty and help to make your customers successful, my main priority.

3. Never require a customer to “sign in” or provide personal information in order to download a datasheet. If you are going to announce to the world that your company offers a certain product, don’t pull a bait-and-switch by subsequently forcing me to give you my email address. It can be optional, but please don’t require it! There are certain companies and product areas where this is common practice, and it always leaves me frustrated (as an engineer and potential customer) and dumbfounded (as a Sales/Marketing person). This is the era of Google, YouTube, HD On Demand, and Wikipedia. Modern culture demands that information be freely disseminated without someone having to remember their password. Therefore, why hide your datasheet? I understand the argument (security, competitive advantage, marketing information, etc), but frankly, I think it is difficult to justify because it leaves customers with memories of a negative website experience…problem. Plus, your competitor might be willing to give out datasheets without the hassle…bigger problem.

These are just a few rules of thumb I try to follow when it comes to datasheets and website maintenance. If you have any suggestions or want to share your own opinions and experiences about the world of spec’ing and datasheets, I’d love to hear them.

Christopher F. Marki received his B.S.E.E. from Duke University in 2002 and his M.S.E.E. and Ph.D. from University of California, San Diego in 2004 and 2007, respectively. While in graduate school, Christopher studied high speed fiber optics and consulted for San Diego start-up Ziva Corporation. Following graduate school, Christopher decided to forego a life in Photonics and opted, instead, to work with his father at Marki Microwave and learn the “family business” of microwave mixers. While at Marki Microwave, Christopher has served as Director of Research and has been responsible for the design and commercialization of many of Marki’s fastest growing product lines including filters, couplers and power dividers. Dr. Marki has authored and co-authored numerous journal and conference publications and frequently serves as an IEEE reviewer forPhotonics Technology Letters and Journal of Lightwave Technology.