Is “Z” the Shape of Things to Come?

ith apologies to the 60’s rock band The Yardbirds for stealing one of their song titles for this month’s column, it is, nonetheless, appropriate.

A NIST (National Institute of Standards and Technology) Tech Beat article recently caught my attention, as it will likely yours: “Engineered Metamaterials Enable Remarkably Small Antennas”.

Wait! What’s that? Is the government now getting into the compact antenna fray? In a word, yes. Borrowing from the release, here are some highlights:

“The National Institute of Standards and Technology (NIST) and partners from industry and academia have designed and tested experimental antennas that are highly efficient and yet a fraction of the size of standard antenna systems with comparable properties.

NIST engineers are working with scientists from the University of Arizona (Tucson) and Boeing Research & Technology (Seattle, Wash.) to design antennas incorporating metamaterials—materials engineered with novel, often microscopic, structures to produce unusual properties.

The new antennas radiate as much as 95 percent of an input radio signal and yet defy normal design parameters. Standard antennas need to be at least half the size of the signal wavelength to operate efficiently; at 300 MHz, for instance, an antenna would need to be half a meter long. The experimental antennas are as small as one-fiftieth of a wavelength and could shrink further.”

Let’s put some of this information in perspective. These claims are being made by credible scientific entities, which, while not intending to offend any other compact antenna designers out there, is a refreshing change. Secondly, at 1/50 of a wavelength and shrinking, these diminutive dimensions offer some staggering possibilities for antennas operating on the lower Ham bands as well as AM Broadcast and Long Wave signals.

Here are some examples of the 1/50 wavelength antennas versus a classic quarter wavelength antenna we might see someday:

Let’s try to put these numbers in perspective. A Standard Broadcast Station operating on 1 MHz (1000 KHz) requires a 234’ antenna if it’s not loaded in some fashion. Using one of these new, electrically tiny antennas, when the technology matures to that point, would produce a comparable antenna that is less than 19 feet! That’s just 8% the height of its predecessor. And, remember the quote from above, “The experimental antennas are as small as one-fiftieth of a wavelength and could shrink further”. Wow.

I used the quarter wavelength antenna example first since it an easy picture to mentally form; the big, tall stick over (classically) 120 buried radials. But, why not use two of these shrunken antennas as a dipole? Sure, why not? Now you have a 160 Meter (1.8 MHz) dipole checking in near 21 feet overall.

You probably just pictured a horizontal dipole, right? That would work great for local and regional communications with a high wave angle (it would typically be much too close to ground to get any good DX angles of radiation), but, flip that dipole 90 degrees and, bingo! You now have a 21 foot tall halfwave radiator that is no longer dependent on radials as the “other half” of the antenna. Very tantalizing stuff!

So, you’re probably wondering where the “Z” thing comes in, then, mentioned at he beginning of the article? Back to the NIST release:

In their latest prototype device, the research team used a metal wire antenna printed on a small square of copper measuring less than 65 millimeters on a side. The antenna is wired to a signal source. Mounted on the back of the square is a “Z element” that acts as a metamaterial—a Z-shaped strip of copper with an inductor (a device that stores energy magnetically) in the center (see photo).”

“The purpose of an antenna is to launch energy into free space,” explains NIST engineer Christopher Holloway, “But the problem with antennas that are very small compared to the wavelength is that most of the signal just gets reflected back to the source. The metamaterial makes the antenna behave as if it were much larger than it really is, because the antenna structure stores energy and re-radiates it.” Conventional antenna designs, Holloway says, achieve a similar effect by adding bulky “matching network” components to boost efficiency, but the metamaterial system can be made much smaller. Even more intriguing, Holloway says, “these metamaterials are much more ‘frequency agile.’ It’s possible we could tune them to work at any frequency we want, on the fly,” to a degree not possible with conventional designs.”

Again, profound statements being made in that last paragraph. 95% efficiency, 8% of the formerly-required height, and frequency agile metamaterials sound like either a gallon of snake oil or science fiction. Given the source of these quotes, I think we can rule out the snake oil and put some cautious optimism into the “fiction” part of the science fiction falling to the wayside as their prototypes drop in frequency from their current 300 MHz down through VHF to HF.

This promises to be a brave new frontier, and, if you happen to be part of this new horizon, we would love to hear from you. Especially, if there are ways us mere mortals can begin experimenting with designs and materials that may help break the HF frequency barrier. With a name like antenneX, you can bet we plan to be front and center to report on and help push forward this promising new technology, to the extent we can.

BEWARE OF CYBER WARFARE
This is a topic that affects us all that browse the Internet and folks need to be better informed about another growth in dangers out there in Cyber Space. Email spam is only one issue and many are aware of that annoyance, plus the dangers of viruses that may infect one's system.

Did you know your Internet browser can be infected too and without your knowledge? This is another battleground we all must deal with in some manner. Being aware is the first and important part of this fight. Infections of browsers usually come in the form of some type of Malware or Spyware transmitted by use of "bots." Our concern is with what is called "bad bots."

If one is browsing a web site containing valuable intellectual content such as ours, an infected browser may run into trouble if the site has safeguards such as that on our servers. Servers can be configured to detect an infected browser and take some sort of counter-action, which may include an abort of the session making the site unavailable until the person's browser is "cured" of such infection. Sometimes the quickest way for a cure is to download another browser and install it "out of the box." It is not likely to be infected and one can continue a session of the desired site. It only takes a few minute to download/install another browser and it's a good idea to have at least one other browser anyway at the ready when browsing. However, one needs to make the effort with more time to remove the bad bot on the original browser. There is software to help remove malware. Just Google “malware” and I’m sure you will find some. Unfortunately, if your browser is infected, you are not able to read this!

What is Malware?
Malware, short for malicious software, is software designed to infiltrate a computer system without the owner's informed consent. The expression is a general term used by computer professionals to mean a variety of forms of hostile, intrusive, or annoying software or program code. The term "computer virus" is sometimes used as a catch-all phrase to include all types of malware, including true viruses.

Software is considered to be malware based on the perceived intent of the creator rather than any particular features. Malware includes computer viruses, worms, trojan horses, spyware, dishonest adware, crimeware, most rootkits, and other malicious and unwanted software. In law, malware is sometimes known as a computer contaminant, for instance in the legal codes of several U. S. states, including California and West Virginia.

Malware is not the same as defective software, that is a software that has a legitimate purpose but contains harmful bugs.

Preliminary results from Symantec published in 2008 suggested that "the release rate of malicious code and other unwanted programs may be exceeding that of legitimate software applications." According to F-Secure, "As much malware was produced in 2007 as in the previous 20 years altogether." Malware's most common pathway from criminals to users is through the Internet: primarily by e-mail and the World Wide Web.

The prevalence of malware as a vehicle for organized Internet crime, along with the general inability of traditional anti-malware protection platforms (products) to protect against the continuous stream of unique and newly produced malware, has seen the adoption of a new mindset for businesses operating on the Internet: the acknowledgment that some sizable percentage of Internet customers will always be infected for some reason or another, and that they need to continue doing business with infected customers. The result is a greater emphasis on back-office systems designed to spot fraudulent activities associated with advanced malware operating on customers' computers.

On March 29, 2010, Symantec Corporation named Shaoxing, China as the world's malware capital.

Sometimes, malware is disguised as genuine software, and may come from an official site. Therefore, some security programs, such as McAfee may call malware "potentially unwanted programs" or "PUP".

Some servers are configured to detect malware attached to your browser and you may find that you are suddenly kicked off the site because of the offending malware. If you don’t know how to remove the malware, it may be best to reinstall the browser or install an alternative popular browser. There are several: MSIE, Firefox, Safari, Opera, all standard Mozilla-type browsers. Installed right out of the box, your browser will no longer be infected.

Again, there is software to help remove malware. Just Google “malware” and I’m sure you will find some.

Malware trends 2010
An annual forecast report by the GeorgiaTech Information Security Center, or GTISC, states that emergent threats to the security of the electronic domain will manifest in more virulent attacks by malware and other terrors.

The accumulation of information will still be the driving force of cyber-crime, as it attempts to infiltrate all possible sectors, the range of which includes newer mobile applications down to more conventional computing. Security professionals also bolster this claim, and anticipate the continuation of cyberspace aggression into the future. The ‘data’ motive is the purpose behind Botnets, Cyber Warfare, Social Network Malware, and VoIP Attacks.

Botnets
Experts say that botnets are evolving in a drastically shorter duration as compared to spam and viruses. The previous year’s GTISC report approximated that botnets comprised ten percent of all computers logged onto the Internet. This ten percent are tainted with malware and ‘controlled’ by various cyber-criminals. This year, the estimated percentage of botnet-associated computers may shoot up to fifteen percent.

Many professionals foresee that conventional military will be increasingly compounded by cyber-warfare in the coming years. They also state that more covert attempts at subversion by unfriendly nations will take the form of electronic-war techniques. Some even proclaim that China has a hand in this, as most bot controllers and malware threats have been tracked down to the country.

Social Networks Malware
Malware objects, the report says, will increase multiple times by this year. Phishing scams, as well as other forms of distribution, are making room for attacks via sites for social networking. Facebook, MySpace, and other sites may be turned into a means for delivering malware.

VoIP Attacks
VoIP technology is another vehicle for disseminating malware. Much like the issues connected with emails in the past, criminals will use VoIP to perpetrate information theft, voice fraud, and numerous scams.

VoIP networks may also play host to botnet attacks, disabling of services, and remote execution of code. The information that people impart over the phone makes it ideal for criminals to take advantage of, for purposes such as identity theft and phishing.

Spyware
This category is as the name implies — spying! Although not as harmful as the malware category, spyware attaches itself to the browser to watch one's browsing activities largely to gather marketing information about your habits. Nonetheless, it's still intrusive and unwanted by most if not all. It can be removed as well. Just be aware it may be riding quietly on your back without your knowledge.

THE PURPOSE OF THIS JOURNAL
In an earlier column, The antenneX Mission I wrote about a subject close to my heart — the purpose of this journal. It had been quite some time since I had reminded our readers of our original purpose when we set out some 21+ years ago.

More than anything else, this journal has always been a “labor of love” for me. It is the reason I founded the antenneX magazine 20 years ago, knowing that running a magazine is a tough business and especially so since I planned to do it without the traditional revenue support from advertisers or outside investors. I wanted this magazine to always be able to write about any issue without concerns of losing the support from any of those type revenues. I am pleased to say, we have never steered from that course one iota. And, as a consequence, we have covered some very controversial developments throughout the past two decades. In the process, we have provided valuable factual information to more than 200 countries, even to the most remote regions of the globe. Hence, our readers are much more informed about the truth about all of the “new” devices as their stories unfolded in the antenna and antenna-related field. For more details, you are encouraged to read my column from September 2006.

Additionally, we were pleased to receive and publish in the October 2006 issue, a very special editorial reaction to my column written by one of our long-term readers and contributors, Dr. Jef Verborgt. Those two articles are located by the following links below:

VISIT THE GUEST ROOMS
The relentless attacks on our web site by pirates, looters, hackers and the like has made it necessary to add more security to protect our material against such piracy. It's only fair that we know who enters the House of antenneX, so our guests will need to provide some minimal information in the process of obtaining a login. This includes using your real active email address without which a login cannot be received. Do not confuse this login with a paid subscription login. They are not the same and your subscriber login will NOT work in the Guest Room areas unless you create it that way. You may choose to create your own login to the Guest Rooms using the same login as your subscription—you have full control over your logins here.

Along with the continuing fight against spam/virii junk, protecting our material and valuable bandwidth against piracy takes up a great amount of our time—time we can't really spare. The Internet is simply not the friendly neighborhood it used to be in the "old days" and more and more security must be installed to counteract these intruders. Thus, we have made the access to the Guest Rooms as automatic as possible for you to manage your own login.

In view of the above, we have overhauled the numerous free and open-access sections that have always been wide open to all of our friends throughout the many years antenneX has been online. But, we must change with the times as the need dictates. I don't think the Internet will become more friendly in the near future and protected sites with logins are fast becoming the rule rather than the exception. To repeat, most would like to know who they invite into their house. The same applies at the House of antenneX. It's really worth the effort!

We have activated a new login system for access to the above guest rooms — and, the login can be totally managed by our guests. Above is a graphic of what you see as a login page to the new consolidated area, "antenneX Guest Rooms." This new page for logins is at this location now and available for your use:

As a result of this new programming, you will be able to obtain your own login, change it to update your info, change your password and delete membership if & when you desire without our help. Of course, the bottom link on the new page provides help if you still need it.

AN INVITATION TO CONTRIBUTORS
antenneX thrives on the contributions of antenna experimenters, ranging from the informal home shop construction project to the theoretical investigation of basic antenna, feedline, and propagation phenomena. Over the years, we have published articles on the use of new or newly adapted materials, known antennas adapted to new circumstances, modifications of antenna structures, basic explorations of both common and unusual antennas, antenna modeling exercises, design improvements, antenna matching techniques from both a physical and mathematical perspective, evaluations of mini-antennas and their underlying theory of operation, new and patentable designs, propagation tutorials, and.... The list goes on, since no antenna-related topic is irrelevant to the readers of antenneX.

At the same time, antenneX has experienced continuous growth in its readership—for which we are appreciative. However, all readers can help us do even better. How? By submitting an article every now and then based on your current antenna work that may be useful at any level to other readers.

Among the engineering and researching readers, there are undoubtedly a number of unclassified and non-proprietary findings that antenneX readers would like to know. Among the practical antenna designers, there are ideas, tests, and numerous other practical findings to benefit our readers. Antenna builders very likely have some techniques to share with other readers. Besides the regular articles, we always have the home work shop column for shorter practical ideas and we always have the invited news and editorial column for information about new technologies, future advances, lost old but good ideas, and personal views on the good to bad things that are happening in the world of antennas and propagation.

If you are uncertain about whether your ideas merit an article, please feel free to send an outline to the general editor/publishers at manuscripts at antennex.com . Do not feel that you must be ready to be a regular submitter to write for antenneX, because we welcome the individual contribution as much as monthly articles. As well, do not believe that the slots in each issue are already spoken for—we shall always make room for a worthy article.

IN THIS ISSUE
We again include many fine articles by our great writing team from around the globe. Now, allow me to introduce this month's line-up of content:

Adjusting Near-Perfect Broadband Antennas for 80-75 Meters
By L. B. Cebik, W4RNL (SK)

In “Notes on Ribbons, Cages, Parasites, and Lines: Broadband Coverage of the 80-75-Meter Band with AWG #12 Copper Wire” in the previous issue of antenneX, I explored some of the methods for obtaining full coverage across the 3.5 to 4.0 MHz span with a single antenna. I re-examined some further options in a QEX column (“Antenna Options”) that opened some additional possibilities offered by combining broadbanding techniques. Some of the methods of matching via combinations of transmission line proved robust enough to allow the use of ribbon or cage constructs with relative small proportions, instead of the very large dimensions required for direct full coverage by the antenna alone. In fact, we were able to obtain 50-Ω SWR curves with values less the 1.5:1, thus meeting the most rigorous requirements of amateur amplifiers having the most sensitive fold-back circuits.

Practical Antennas: Part 2.11
By Marcel H. De Canck, ON5AU

The ionosphere plays a tricky but an important role to our radio communications, and there is very little we can do about it. But there is plenty you can do about having a good and efficient antenna system. Yes, antenna system, it’s not the antenna itself but the whole part as transmission line, and matching properly the transceiver and the antenna to the transmission line. It is a breath-taking concept that a simple length of wire or rod or tube can transform electrical energy into invisible radio electro-magnetic waves that can cross the space at the speed of light.

How does an antenna system works? Why does the antenna radiate electro-magnetic waves? These questions I heard many times and the answers are not given with few words. Never-the-less, many books and some of great weight and complexity have been written about antennas and many antenna types have been developed and build. Often it is not comprehensive to the layman to fully understand the whys and hows of the radiation capabilities of an antenna and these counts even for the simplest ones like a dipole or a groundplane. Also I often hear many times misconceptions about antenna properties and characteristics. To start with, understanding why and how a simple antenna effective radiates will be explained in a clear view. The dipole is the best antenna to do that and once the secrets of the dipole characteristics and properties are fully understood it will be much easier to have a clear insight of the hows and whys of more complicated antennas.

The first episodes will handle completely about antenna fundamentals mostly with the half wavelength dipole as study example. The dipole is also often a part element of more complicated antennas such as a Yagi and others. In particular for the low frequency bands, the dipole is used by many radio amateurs as transmitting or receiving antenna and its many practical installations and shapes will be fully studied and explained in a chapter later on. In fact many other antenna types will become subject to explanation as the antenna story develops.

NewcomerNotes: Antenna Supports
By Robert Gulley, AK3Q

While we often talk about getting creative with antenna design, sometimes we have to get creative with how we support our antennas and with how they are run. If life were perfect we would all have acres of land upon which to build enviable antenna farms, with one or two antennas for each band we sought to work. Mind you they would all be strung with hardline or super-low loss ladderline, with switching relays, rotors, and crank-up towers. And of course, where useful, full wave loops as needed supported by telephone poles or the like.

Getting creative isn’t just about antenna design and placement, but also about how antennas get supported. I want to talk a bit about antenna supports this time around, and suggest ways in which ordinary items around the house or found at the local hardware store can increase your antenna options. Trees and towers work great, but sometimes they are just not available. Supporting an antenna doesn’t have to be costly—it just needs to work. With this in mind, let’s look at some economical support options, some of which are even free.

The “Magic” Rhombic
By Robert C. Wilson, AL7KK & VE7ZKK

Do you want an all-band high frequency radio amateur antenna that has real gain, is cheap and is easy to build? This one described can operate on all ham frequencies from 80 meters to 10 meters. It is in the rhombic category but is smaller than most other antennas of that type and likely will fit on your property. Unlike almost every other rhombic, this one has proper beam patterns that uniformly point toward the far end apex on every band from 30 meters to 10 meters, and reasonable omni directional radiation patterns on 80 and 40 meters. It is particularly remarkable; indeed it seems almost magical that the patterns are excellent, without any splitting on every one of six amateur bands.

I have looked at quite a number of rhombics in my 63 years as a ham, engineer, and as a Voice of America advance planner. I was happy to see that for some strange reason everything came together just right with this one special rhombic configuration. The “Magic” Rhombic is simple to build.

The New Super-Delta: Part 2
By Edward J. Shortridge, W4JOQ

The Super-Delta matching configuration is a completely new method of broad-banding radiators for use in some of the wider radio amateur bands, such as the 75/80-meter, 10- and 6-meter bands. The previous article, Part 1, shows the evolution from the Bottom-couple (low impedance), to the Super-Delta. This Super-Delta match provides all of the key ingredients necessary to adjust antennas for the desirable bandwidth, the amount of coupling to provide the best SWR, and the means of matching to a 50-Ohm Source.

It has a very simple configuration, the component costs are quite low, and there are only low loss components involved. The far-field radiation is not impaired in any way by the configuration used, but it does enhance it because of the simple straightforward design.

Part 2 presents horizontal Super-pole antennas for the 75-meter and the 75/80-meter bands mounted at a variety of heights. Illustrations are provided to assist in adjusting the antenna when mounting it. Additionally, Inverted-V antennas are presented at different heights and in a variety of configurations.

Circularly Polarized Antennas for Ham Radio
By Grant Bingeman, P.E., KM5KG

Circularly polarized antenna system where both the transmitting and receiving antennas are CP can provide some advantages when compared to a typical linearly polarized RF antenna circuit. The reader is cautioned that this report as a series of papers is long, highly technical, and requires careful study. The author hopes the reader will be inspired to experiment with HF CP designs based on the concepts and practical examples described in this series of articles. Circularly Polarized commercial FM and TV transmitting antennas became popular in the 1970s. However CP has seen little use in ham radio applications. This is surprising considering the enormous benefits.

Well, there you have it, folks—thanks for listening and remember, the reading lamp is always on for you in the reading rooms. If I can be of further help, I'm just a Stone's Throw! away. -30-

Frequency	~Ľ Wavelength	1/50 Wavelength
7.0 MHz	34’	2.67’
3.5 MHz	67’	5.35’
1.8 MHz	130’	10.4’
1.0 MHz	234’	18.72’
500 KHz	468’	37.4’
250 KHz	936’	74.9’