Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 3
2 First Day (Open) The presentations were followed by discussion periods during which questions were posed and answered and ideas were exchanged among the participants. Summaries of these discussions sometimes do not follow their specific order of occurrence during the meeting, thus allowing like topics to be synthesized (e.g., discussions of entities engaged in antenna design activities). The first three presentations had one speaker each. The last topic was covered by two speakers. FUTURE OF ANTENNAS Lon Pringle, director of the Signature Technology Laboratory at Georgia Tech Research Institute, was the speaker. His key point was that the "future of antennas is now" and that several enabling technologies, most notably the increase in computational power, are combining to make the present an era of dramatic improvements in antenna performance." Signatures dominated 20 years ago, and then technology really started to accelerate. Apertures are solved, but the electronics are still maturing to enable utilization of the future capability of the antenna. Everyone likes low frequency, but big antennas are needed, in his view. Pringle reemphasized a major element of his key point as follows: the ability to predict the performance of antennas by calculation has taken over the prior slow process of building (by intuition) and testing. The fact that the United States can now model how an antenna is going to perform is really significant and a great breakthrough. Enabling technologies include electromagnetic modeling, speed of computation, and micro-electronics; he affirmed that these tools are enabling design and discovery. He further amplified the importance of computation by noting that the future of antenna design is in a person who understands electromagnetics and works with a computer to design a new antenna (i.e., person plus computer). In 5 to 8 years, fast commercial codes will give most radar houses this capability. His many other comments included that (1) a computer can tell what values of resistive sheets to place in cavities; (2) some connected arrays have coupling that works for them rather than against them; (3) challenges include getting rid of heat, packaging, wide-band electronics, and beam-formers; (4) optical switches can optimize performance (e.g., switch bands, steer antenna, use several beams or combine them into a more powerful one); and (5) there is a revolution in ground-plane structures-- hopefully, with these and active meta-materials, one can build an adaptable antenna, which actually reacts to the environment (e.g., a missile is also the antenna). Discussion After Presentation1 Q: What kind antennas for UAVs? A: Low gain. Small UAVs just can't carry a heavy dish antenna. Larger UAVs have dish antennas. Q: Will better materials come into play? A: Magnetic and meta-materials. But we must have area, which some say we can get along without--be skeptical. 1 Unless specifically stated otherwise, the speaker answered all questions. 3
OCR for page 4
4 SUMMARY OF A WORKSHOP ON THE FUTURE OF ANTENNAS Q: How about advances in other countries or areas, such as Europe or China? A: If need is there, then the Chinese will go for it. Right now, they need to work on building the infrastructure (e.g., foundries) to support the technology. Regarding ultra-wideband phased arrays, ultra-thin low-frequency antennas, reconfigurable ground planes for low-frequency applications, and reconfigurable antennas, the Europeans are working in these areas. This information is also published, and so we can research where Europeans are going. Q: Are you seeing really interesting publications and new innovative concepts outside the United States? A (by James Armitage, attendee): When it comes to who is producing the most, then it is China. However, although quantity is high, quality is not there yet. At the same time, the Chinese are catching up and will eventually be at the same level as we are; many Chinese working in this field went to school in the United States. They are going home and applying in China what they learned here. Don't underestimate computing resources outside the United States. The Chinese are building foundries like crazy to feed the auto industry worldwide. It is all money driven and requires large investments. Q: What countries around the world are doing this type of work--China, India, Russia, Israel, France, Germany? A (by James Armitage and Gilman Louie): We need to watch where the money is going. We have been spending more money, by orders of magnitude, than other countries in developing these types of technologies. Now, when we are not spending as much, and other countries decide to make heavy investments, they will catch up quickly. Most of the professors in China received their PhDs in the United States. Now they are going back to China to teach the next generation of engineers. This also applies to other regions of the world (e.g., Europe and India). COMMERCIAL STATE OF THE ART OF WIRELESS COMMUNICATIONS AND CONTROL Sebastian Rowson, chief scientist at Ethertronics, was the speaker. His privately held company manufactures million of antennas per week (e.g., for cell phones, laptops, medical devices). They have moved from simple designs and manufacturing challenges to active, reconfigurable antenna systems defined and optimized for commercial applications. "Active antenna systems technology applies to any wireless device. Mobile device data throughput increased (46 percent increase demonstrated in an access point)." Challenges are numbers of applications supported and very small volumes (e.g., 2 cubic centimeters with active antennas). Ideally, active and reconfigurable antennas can adjust automatically to changes in the environment enveloping the device (e.g., when a hand is on a phone). For the future, Rowson noted that a goal is to integrate everything inside the phone; the antenna is the link to outside signals. If switching from different base stations can be minimized by optimizing for only one base station, effort and resources can be freed up. Associated challenges involve development of new software to support the antenna. Again, the aim is to design everything together and have elements that adjust "on the fly" so as to achieve more capability with these systems. Discussion After Presentation2 Q: Where have you seen more gain in technology advances? A: Probably in filters. Already a lot of work has been done on power amplifiers, but there are still opportunities for improvement. Q: How transparent to the user is a change in modes? A: It is very fast; the user does not know it is happening. Q: Are any of these things dependent on materials? A: Mostly on design, but in some cases they are dependent on new semiconductor technology. Q: How about jamming? A: The hope is that the FCC is keeping others off these frequencies. We're not looking closely at jamming. 2 Unless specifically stated otherwise, the speaker answered all questions.
OCR for page 5
FIRST DAY (OPEN) 5 Q: Are there safeguards to limit power coming from antennas? A: The only way to solve this issue is to reduce power. Q: What's next, most interesting? A: Innovative research and development is done at Ethertronics (e.g., switching) to anticipate what the market is going to look like. However, it is customer driven when it comes to producing new designs for antennas--approximately 200 new designs each year. Medical device drawers (metal) were challenging; each had to have six antennas. Q: Does Ethertronics have a single point of failure in its process, such as raw materials? A: Not that we can see. The belief is that nothing will really stump Ethertronics; it has such a wide variety of resources. Q: How about hiring the right engineers to work for Ethertronics; has that been difficult? A: Yes. Now the company hires graduate students and trains them, enabling new employees to fit well into the company environment. Grants help fund these training sessions. There is also recruiting from local colleges (e.g., San Diego State University). Q: How much does Ethertronics work with international companies? A. The company shows some current and advanced designs to companies in various countries. Technology shared with each country depends on the relationship and on the amount of cooperation that has occurred with that company. Samsung and Ethertronics have a good relationship based on design cooperation and past experience. General Discussion on Several Topics by Attendees Individual attendees and speakers then generally discussed several topics and questions. Some participants noted that the future is driven largely by fancier algorithms but that other frequency bands will be needed. NATICK (U.S. Army) is interested in battlefield monitoring. Commercial is going Blue- Tooth (for heart-rate, breathing, skin temperature monitoring). When it comes to physiological monitoring, some participants wanted ubiquity and ease of use. Some participants suggested a need to figure out how to move the data and store it effectively for easy analysis. Some challenges facing the industry: Should data all be on the same network or on different networks? Where should we leverage the infrastructure that exists? MILITARY STATE OF THE ART OF WIRELESS COMMUNICATIONS AND CONTROL Robert Newgard, director of Advanced Radio Systems, Rockwell Collins, was the speaker. Rockwell Collins serves two markets--commercial and military. A publicly traded company, it is there for shareholder value; the commercial side is becoming an early adapter of new technologies. Newgard opened with military radio objectives (i.e., cost-effective capabilities, support for operational needs). More specifically, today's military requires multi-mode, multi-channel, upgradable, networked, remotely configurable, actionable information; broadband; low power, high performance; geo-location (for blue- and red-force tracking); and ultimately, any waveform, any time, any place. He also addressed software-defined radios, noting that any waveform can be loaded. Newgard also pointed out that an array of technical challenges exist for military systems: today's fielded radios use large radio frequency (RF) front ends and components that can accommodate the worst- case requirements ("corner" cases are difficult). Future designs need adaptable and reconfigurable RF front ends; flexible and dynamic RF performance; real-time optimization and performance; low observability; and the characteristic of being capabilities driven, not requirements driven. He explained how to do more with less. More capability with fewer assets (e.g., we have a lot of capability, but we cannot fix all issues by throwing more hardware at the problem). If one throws hardware or software at a problem, the solution could become too expensive (especially in the software realm).
OCR for page 6
6 SUMMARY OF A WORKSHOP ON THE FUTURE OF ANTENNAS Discussion After Presentation3 Q: Is the point solution going to be cheaper and better than software-defined radio? A: Yes. Q: Does the manufacturer reconfigure, or does the operator do that? A: The radio does it by itself. Q: How much red force or outside threats do you factor into your research and development? A: Quite a bit; we try to vector threats into our production and technology and regularly consult with people in the field (engineers in the battle-space) for design. We also have cleared staff that can work on classified projects. Q: Is there an opportunity for photonics in the front end? A: Yes, small power. Q: What fraction of radios are software defined? A: Somewhere in the 25 percent range are software defined, and it is not growing fast. Q: How far behind Android and iPhone are the military? A: Not that far. Q: What is U.S. technology vulnerability in your field? A: The biggest concern is what the Department of Defense (DoD) is doing to develop requirements. DoD acquisition managers are developing requirements that may not be realistic. Instead of engineers, there are people who lack the technology expertise to develop proper requirements. They have business majors instead of engineers working on this, people who do not have the necessary expertise. People need intuition, knowledge, and experience to create effective requirements. Q: What percentage of Rockwell Collins engineers are foreign nationals? A: It has no foreign nationals; most of the engineers have projects that involve work requiring a clearance. Prompted by questions and exchanges among participants, Newgard made the following general comments: Our biggest concern going forward is the skill set, not the technology. It is more about having the engineers who are capable of doing what needs doing, and being passionate about it. Yes, Rockwell Collins is having problems hiring qualified candidates, and now tends to grow its own people (e.g., hire engineers while they are going through college, use internships, and then train them). Also, a large portion of the Rockwell Collins engineering design team is going to retire in the next decade. We need capable engineers who are "committed experts." Regarding the Federal Acquisition Regulatory (FAR) process, there are many problems that involve one hand not talking to another. F-22s don't talk well to legacy systems. The Navy builds systems that do not talk to the Army's. On top of that, the FAR process does not allow a lot of critical thinking to determine effective tradeoffs (make tough calls with limited resources). And when the requirement developers lack engineering experience, it creates a somewhat confusing environment that inhibits innovative thinking. FUTURE TRENDS IN ANTENNA DESIGN AND WIRELESS COMMUNICATIONS AND CONTROL Timothy Hancock, assistant group leader, Analog Device Technology, Lincoln Laboratory, MIT, was the first speaker. He was followed by Yahya Ramat-Samii, Northrop Grumman Chair in Electromagnetics at UCLA, who spoke by phone. Hancock reviewed trends in the use of antennas that enable improved communications, data transfer, soldier health monitoring, and methods of data collection. He briefly described techniques for overt and covert methods of standoff data collection (e.g., reduce transmitted power and energy per bit, mitigate or exploit in-band interference), noting that it would be good to get away from the concept of "that's my band, so don't use it." Turning to multiple-input, mutiple-output (MIMO) wireless systems, he introduced the approaches of spatial multiplexing, diversity coding, and pre-coding and then pointed out several advantages of MIMO (e.g., improved data transfer from or to a disadvantaged transmitter or receiver and mitigating interference). Challenges in implementing MIMO systems include the design of antennas, receivers, and transmitters; much computing power and math are involved. 3 Unless specifically stated otherwise, the speaker answered all questions.
OCR for page 7
FIRST DAY (OPEN) 7 Rahmat-Samii (using nearly three dozen slides) described novel outside-of-the-box concepts for antennas--from tiny ingestibles to large space antennas. UCLA's antenna research, analysis, and measurement laboratory is organized in five fields: personal communications; medical RFID (RF identification); remote sensing; electromagnetic band gap (EBG), photonic band gap (PBG), nano, and MEMS (microelectromechanical systems); and analyzing, optimizing, and measuring. The laboratory (in cooperation with other institutions) is advancing miniature antenna concepts as well as large antenna concepts. One of his key points was that "we can optimize antennas for almost any need!" Rahmat-Samii highlighted the many conflicting challenges of miniaturization (e.g., low profile or low volume, with or without ground plane, single frequency or multifrequency, narrow or broad band, single or multiple elements, low or high cost). Approaches for miniaturization included low profiles using EGB, folding structures, incorporating switches, hybridization of the above, and stored energy utilization. He mentioned advances in RFID, including platform-tolerant tag designs, medicine-monitoring RFID systems, and medical diagnostics and sensing. He also covered advances in meta-materials, including double-negative materials, EBG structures, and artificial complex ground planes. Questions and General Discussion4 Q: For wearable textile antennas, where do you see this research going? A: Two fronts, embroidery machines and wearable designs (e.g., communications on clothing, such as for firemen). Q: In medical applications, are you looking at RFID tags embedded inside the body for medical scans? A: Designing these types of chips, which create the communication link, is a challenge. However, this area of study is emerging, and the UCLA team is examining this application. Q: International work? A: Europeans are doing interesting work (e.g., research on antennas and establishing a school of antenna engineering for worldwide Ph.D. students). The Far East (e.g., Singapore) is working in areas of miniaturization and multi-band design plus medical applications (biotelemetry). The Japanese are trying to reduce the cost of arrays and are also harvesting electromagnetic energy (e.g., charging cell phones from energy in the environment). Finally, China is doing research and producing various products. 4 Unless specifically stated otherwise, the speaker answered all questions.