Unknown Editor

What's with the mask? He's not fool enough to give up his day job, that's what!

The Haiku contest page has been moved here.

Microwave career-killers

Good one, Mel!

This page will help guide your career path in the field of microwave engineering. It's such a cool topic that we have simultaneously added it to the Microwave Encyclopedia!

What technologies should you stay away from if you want to avoid precipitated upon by a future pink-slip blizzard? Without a single doubt, this page covers a topic that will NEVER be covered in any trade journal, IEEE paper or government solicitation. What can we say, we're there for you!

After we review these dead or dying technologies, your homework assignment is as follows: practice in front of a mirror repeating the response that is needed during meetings when a particular career-killing topic comes up... instead of just saying "no way Jose", just say "good one!" but try to minimize the smirk. Then if you are called on the carpet later by Mayor McCheese, you can play your comments either way, either "good" in the sense that Michael Jackson used the word "bad", or good as in, "not altogether crazy". Remember never to say "not bad" in front of any Limeys, or they will surely misinterpret this as the highest possible praise. Can you dig all that? For this excellent use of the quirks of the English language, we dedicate this page to Heidi and Eric who are masters of many two syllable responses.

It is only fair to warn you, the information provided here was surely fueled by one of "Mr. Gordon's excellent products" (to quote Hemingway). If you disagree, or have some other suggestions, chime in mate, or sponsor a page on your particular sacred cow and maybe we'll change our opinion. Our apologies if we step on someone's sacred cow and they can't take a joke, but better you hear about what people really think here at Microwaves101 than you hear from Mayor McCheese later when he figures out he's been wearing the Emperors New Clothes. There's an image we didn't need!

Like Charles Dickens' best work, we'll divide the topic into three tenses: past, present and future. Perhaps another way to look at these technologies is in the three chronological phases of technology: unbridled enthusiasm, backpedaling, despair, and blame. Hey, that's four!

The ghost of career killers past

IMPATT diodes (so called "solid-state transmitters")

IMPATT diodes have some interesting properties. Under certain conditions they can amplify a signal by about one dB. So to make a transmitter, you need to efficiently combine a chain of one zillion IMPATT diodes, using a low-loss technology such as machined waveguide. Forgedaboudit. Figure out another way. You are out of your mind.

Josephson junctions

Does anyone even remember this stuff? Or was it just a nightmare like cold fusion?

Aluminum silicon carbide (AlSiC)

AlSiC was received with great fanfare in the 1990s. Net-shaped housing with matched CTE to GaAs. Where are the purveyors and early adopters of this technology now? Haven't seen them!

The problems that have persisted include the inability to maintain a minimum aluminum skin thickness. Wherever the silicon carbide pokes through, plating won't stick. Poor plating means no chance of hermeticity, because you will have to braze in some feedthroughs because you sure can't fire in glass above the melt temperature of the housing. Also, the reality of net-shaped eventually meant "near-net-shaped", which means you might as well go to a machine shop, but you should pick something to machine that won't ruin your tools like silicon carbide will. Recall that silicon carbide is the main ingredient in sandpaper!

Integrated features on alumina

Over the years several thin-film vendors have tried to move up the food chain, offering filled "hermetic" via holes, airbridges, multilayer interconnects and even MIM capacitors. Guess what? This technology is low yielding and tres expensive. Where is MIC Technology when you need them?

Today's career killers

Automotive radar (a.k.a. adaptive cruise control or "car radar")

Maybe this should already move to the "past tense". Sure would be nice to be able to kick back and let some Gunn diode apply the brakes when you're creeping up on the car in front of you. Better yet, why don't you put down the cell phone and pay attention to what you are doing?

The automotive radar idea has been around for over 10 years. As near as we can tell, no one in North America ever made a dime off of this. One problem is that radar companies are used to dealing with juice defense contracts which pay cost-plus for development. If you ask Ford for such a contract, they will respond "good one!"

So where does this leave you if you went out on a limb and built a prototype radar for a car? You get to shop around your failed project to defense companies, because only Uncle Sam could afford something that you could produce at a profit. How many "lunch and learn" seminars do you want to provide to LockMart, Boeing, and Northrop?

Here's another thought. Spin off the company, maybe then you, the dragooned employees and the stockholders will make some real dough. This is the case of Valeo Raytheon Systems. Ever hear of them? One other thought... repackage your adaptive cruise control as a blind spot detector...

Low temperature co-fired ceramic (LTCC)

LTCC offered to provide us all with a low-cost, three-dimensional interconnects for microwave modules. No doubt about it, some of the coolest hardware to ever be demonstrated uses LTCC. So what is the problem?

Shrinkage is one issue. Or rather, shrinkage tolerance. If every circuit shrank the same way, every time, maybe you could talk about high yield. Or you could just put up with it and accept low performance.

Post-plated metal is another problem. The cofired metal doesn't always have the properties that one would want, for example, for soldering or wirebonding.

But the primary problem is: ceramic sure is expensive compared to soft substrates like PTFE... so what happens when you evolve to a multilayer ceramic? It gets more expensive! What happens when you evolve to multilayer soft-board? You kick ass and take names! If someone tells you LTCC is affordable, you can quote us here... "good one!" Sure you can make some hero results with LTCC, but it will never be cheap. Look for a soft-board solution.

MEMS

It is fair to say that MEMS may yet prove to become a billion dollar per year microwave component, especially in the past two years when many of the shortcomings seem to have been addressed. But so far we have been less than impressed with the notion that MEMS was going to revolutionize microwave industry. Wake us up when this happens! Check out the Riddle of MEMS...

High voltage GaAs

(This was contributed by someone that surely wants to remain anonymous...) For a few million bucks you can always tease another volt of operation out of GaAs pHEMT power amps. But read the writing on the wall. GaN transistors are coming that will operate at 50 volts, and GaAs pHEMT will slowing but surely become a niche market, the way MESFET is treated today.

Future career killers

Carbon nanotubes

Here is a lab curiosity that is looking for a problem to solve... is it a transistor? or a heat sink? or a mixer? All together now: "good one!"

Anything that involves diamond

We've seen two ways to use diamond in microwave technology both of which are potential career killers. The first is as a wide bandgap semiconductors. But diamond doesn't offer a whole lot higher performance than silicon carbide, which is cheaper by a factor of Avogadro's Number.

The second microwave application that diamond might be bandied about is as a low-cost heat sink. Hey, diamonds are called "ice" for a reason, this crystal has staggeringly high thermal conductivity. But when deposited as an amorphous film, the reduced thermal conductivity is not that much better some cheap metals.

Last, any industrial application of diamond will remind the public that diamond is just carbon, and should be cheap. Then you will have to deal with the DeBeers family, which wants us all to pretend that diamonds are worth multiple paychecks per carat. Some South Afrikaner with a crooked nose might come and break your knuckles for messing with diamond's artificially high price. Yikes!

On-chip MEMS tunable matching networks

Three-dimensional MMICs

The premise here is that you could drive down the cost of a MMIC power amp by using Group III-V semiconductor only for active devices, and stacking matching networks on multiple top layers. Good one!

You might notice the use of the word "three-dimensional" implies horizontal and well as vertical interconnects. And transitions thereof. The devil in these details is that vertical/horizontal transitions always stink. Keeping everything in the horizontal plane will give better performance, trust us.

That's all for now! Send us some more ideas for this page please!

Check out the Unknown Editor's amazing archives when you are looking for a way to screw off for a couple of hours or more!