Electromagnetic Breakthrough: Scientists Design Antenna ‘on a Chip’

Anechoic test chamber.  University of Cambridge.

As reported by Phys.org: A team of researchers from the University of Cambridge have unraveled one of the mysteries of electromagnetism, which could enable the design of antennas small enough to be integrated into an electronic chip. These ultra-small antennas - the so-called 'last frontier' of semiconductor design - would be a massive leap forward for wireless communications.

WiFi antenna etched on a printed circuit board.

In new results published in the journal Physical Review Letters, the researchers have proposed that electromagnetic waves are generated not only from the acceleration of electrons, but also from a phenomenon known as symmetry breaking. In addition to the implications for wireless communications, the discovery could help identify the points where theories of classical electromagnetism and quantum mechanics overlap.

The phenomenon of radiation due to electron acceleration, first identified more than a century ago, has no counterpart in quantum mechanics, where electrons are assumed to jump from higher to lower energy states. These new observations of radiation resulting from broken symmetry of the electric field may provide some link between the two fields.

Dipole antenna radiation pattern.

The purpose of any antenna, whether in a communications tower or a mobile phone, is to launch energy into free space in the form of electromagnetic or radio waves, and to collect energy from free space to feed into the device. One of the biggest problems in modern electronics, however, is that antennas are still quite big and incompatible with electronic circuits - which are ultra-small and getting smaller all the time.

"Antennas, or aerials, are one of the limiting factors when trying to make smaller and smaller systems, since below a certain size, the losses become too great," said Professor Gehan Amaratunga of Cambridge's Department of Engineering, who led the research. "An aerial's size is determined by the wavelength associated with the transmission frequency of the application, and in most cases it's a matter of finding a compromise between aerial size and the characteristics required for that application."

Another challenge with aerials is that certain physical variables associated with radiation of energy are not well understood. For example, there is still no well-defined mathematical model related to the operation of a practical aerial. Most of what we know about electromagnetic radiation comes from theories first proposed by James Clerk Maxwell in the 19th century, which state that electromagnetic radiation is generated by accelerating electrons.

However, this theory becomes problematic when dealing with radio wave emission from a dielectric solid, a material which normally acts as an insulator, meaning that electrons are not free to move around. Despite this, dielectric resonators are already used as antennas in mobile phones, for example.

Dialectric patch antennas are already in use by GPS devices.

"In dielectric aerials, the medium has high permittivity, meaning that the velocity of the radio wave decreases as it enters the medium," said Dr Dhiraj Sinha, the paper's lead author. "What hasn't been known is how the dielectric medium results in emission of electromagnetic waves. This mystery has puzzled scientists and engineers for more than 60 years."

Working with researchers from the National Physical Laboratory and Cambridge-based dielectric antenna company Antenova Ltd, the Cambridge team used thin films of piezoelectric materials, a type of insulator which is deformed or vibrated when voltage is applied. They found that at a certain frequency, these materials become not only efficient resonators, but efficient radiators as well, meaning that they can be used as aerials.

The researchers determined that the reason for this phenomenon is due to symmetry breaking of the electric field associated with the electron acceleration. In physics, symmetry is an indication of a constant feature of a particular aspect in a given system. When electronic charges are not in motion, there is symmetry of the electric field.

Micro antenna

Symmetry breaking can also apply in cases such as a pair of parallel wires in which electrons can be accelerated by applying an oscillating electric field. "In aerials, the symmetry of the electric field is broken 'explicitly' which leads to a pattern of electric field lines radiating out from a transmitter, such as a two wire system in which the parallel geometry is 'broken'," said Sinha.

The researchers found that by subjecting the piezoelectric thin films to an asymmetric excitation, the symmetry of the system is similarly broken, resulting in a corresponding symmetry breaking of the electric field, and the generation of electromagnetic radiation.
The electromagnetic radiation emitted from dielectric materials is due to accelerating electrons on the metallic electrodes attached to them, as Maxwell predicted, coupled with explicit symmetry breaking of the electric field.

"If you want to use these materials to transmit energy, you have to break the symmetry as well as have accelerating electrons - this is the missing piece of the puzzle of electromagnetic theory," said Amaratunga. "I'm not suggesting we've come up with some grand unified theory, but these results will aid understanding of how electromagnetism and quantum mechanics cross over and join up. It opens up a whole set of possibilities to explore."

Si doped 4 inch VGF-GaAs crystal grown in HMM

The future applications for this discovery are important, not just for the mobile technology we use every day, but will also aid in the development and implementation of the Internet of Things: ubiquitous computing where almost everything in our homes and offices, from toasters to thermostats, is connected to the internet. For these applications, billions of devices are required, and the ability to fit an ultra-small aerial on an electronic chip would be a massive leap forward.

Piezoelectric materials can be made in thin film forms using materials such as lithium niobate, gallium nitride and gallium arsenide. Gallium arsenide-based amplifiers and filters are already available on the market and this new discovery opens up new ways of integrating antennas on a chip along with other components.

"It's actually a very simple thing, when you boil it down," said Sinha. "We've achieved a real application breakthrough, having gained an understanding of how these devices work."

Metamaterial Radar Lens May Improve Car and Drone Vision

As reported by MIT Technology Review: Radar instruments that can be used that way are normally bulky and extremely expensive. Echodyne is working on a device that is compact and cheap enough to be used widely.  

Radar systems work by sending out radio waves and using the echoes that bounce back to create an image of an object. Some radar systems use electronics to actively steer their outgoing radio waves, instead of just mechanically sweeping a beam in a fixed pattern. This lets them simultaneously scan the sky for objects and track specific ones with high accuracy. But the complex devices normally needed to steer radio waves around, known as phase shifters, make such electronically scanning radar expensive and bulky.

Driscoll’s drone carries an electronically scanning radar instrument that doesn’t have a conventional phase shifter. The outgoing radio waves are steered with a much simpler device, built using techniques borrowed from a relatively new area of research on what are known as metamaterials.  

This drone has an advanced electronically scanning radar on board, equipment usually much too bulky and expensive for such small craft.

Metamaterials provide a way to get around many of the physical limitations that have previously defined how engineers could control radio, light, and sound waves. For example, while conventional lenses need their characteristic shape to bend light rays into focus, a metamaterial lens can bend light the same way while being perfectly flat.

Metamaterials are made from repeating structures that are smaller than the wavelength of the electromagnetic radiation being manipulated. Echodyne makes its metamaterials by tracing out repeating patterns of copper wiring on an ordinary circuit board.

A board with multiple layers of such wiring can direct radar beams. And applying different voltages to some parts of the wiring makes it possible to actively control the beam as a phase shifter would. “Any printed circuit board manufacturer could produce these,” says Driscoll.

The radar systems used by the military typically start at around $100,000, says Eben Frankenberg, CEO and another cofounder of Echodyne. He says his company hopes to mass produce compact radar systems that cost only thousands of dollars.

Driscoll says that could make scanning radar become a standard sensor for vehicles and robots. Some prototype autonomous cars, including Google’s, use spinning laser sensors (LiDAR) to watch the world around them in 3-D. That technique can map the world in very high resolution, but its range decreases in fog or snow. Radar doesn’t have that limitation, says Driscoll.

Echodyne also plans to offer its systems to the military, and to replace the radar already in use commercially: the spinning dishes seen on ferries and other boats that create simple maps by sweeping a beam around, for example, or the small fixed sensors in some cars that allow an adaptive cruise control system to keep a safe distance from the car ahead.

Echodyne was created by the patent licensing company Intellectual Ventures. In 2013, Intellectual Ventures set up a unit dedicated to building a portfolio of patents for metamaterials, and to figuring out how to commercialize them. Echodyne has also received investment funding from Microsoft cofounder Bill Gates, and venture capital firm Madrona Venture Group.

David Smith, a professor at Duke University who researches metamaterials and has worked with Intellectual Ventures, says that Echodyne’s approach provides very flexible ways to control radio waves. The company’s biggest challenge, he says, is to craft complete radar systems that can compete in the market. That means matching the performance of very high-end systems used by the military today to succeed in the defense market, and carefully controlling costs for applications in the car industry.

Genetic Algorithms Have Calculated What the Ultimate U.S. Road Trip Looks Like

As reported by The Washington Post: Who needs an atlas when you have an algorithm? Data tinkerer Randy Olson, who is now known across the internet for developing the optimum search path for Where’s Waldo books, has used this same algorithm to compute the optimal American road trip.

At the urging of Tracy Staedter from Discovery News, Olson set out to find the quickest driving route that would stop at a national natural landmark, national historic site, national park or national monument in all of the lower 48 states. He also included Washington, D.C. and added another stop in California to get to a total of 50 stops.

Calculating the fastest way to drive between all 50 landmarks – 2,500 individual routes – could theoretically take forever by hand, but Olson used the same genetic algorithm he used to find a search pattern for Where’s Waldo. This algorithm starts with a handful of solutions, takes the best one, and then compares that to other solutions until it can’t find a better one. The result is the route you see above, which includes stops at the Grand Canyon, Pikes Peak, the Alamo, Mount Vernon, Graceland, the White House, the Statue of Liberty, and much more. You can start in any state and follow the path in either direction.

If you didn’t sleep, stop or hit traffic, Olson calculates that this would take roughly 9.33 days of driving. In reality, you probably need a good two to three months to do justice to this epic American road trip.

Olson also created a bonus map with a route through popular U.S. cities, which you can see here. 

Sierra Nevada's Dream Chaser Could Land at Ellington Space Port

As reported by the Examiner: Despite having been rejected in NASA’s commercial crew program, Sierra Nevada has been very busy trying to develop its lift body spacecraft, the Dream Chaser. Having rolled out a smaller, cargo version of the spacecraft for the second round for contracts for commercial cargo to the International Space Station, the company has amended the unfunded Space Act Agreement with NASA to add a closeout review milestone that would help transition the Dream Chaser from the preliminary design review to the critical design review step. Finally, Sierra Nevada announced a new agreement on Tuesday with the Houston Airport System to use Ellington Spaceport as a landing site for the cargo version of the Dream Chaser.

The Dream Chaser had attracted the interest of many space observers when it was competing for a commercial crew contract because of some of its unique characteristics. The Dream Chaser would launch on top of a rocket, such as the Atlas V, and fly to the International Space Station or some other destination in low Earth orbit. But it would then reenter the Earth’s atmosphere and land on a runway, just like the space shuttle used to do. 

The Dream Chaser lost out to the SpaceX Dragon and the Boeing CST-100, two space capsules that would land vertically in the same manner as Apollo spacecraft.

If the Dream Chaser wins the second round of the commercial cargo contracts, it would launch from the Kennedy Space Center, deliver cargo to the ISS, and then take cargo such as the results of experiments. It can also be used as an unmanned flying laboratory, making it “an ideal test bed for biomedical, pharmaceutical, cellular and genetic research payloads.” Ellington Space Port would be in proximity to a number of customers, including NASA’s Johnson Spaceflight Center, the Houston Medical Center, and various universities and private businesses.

The Robotics Age: Planes Without Pilots

As reported by the New York Times: Mounting evidence that the co-pilot crashed a Germanwings plane into a French mountain has prompted a global debate about how to better screen crewmembers for mental illness and how to ensure that no one is left alone in the cockpit.  

But among many aviation experts, the discussion has taken a different turn. How many human pilots, some wonder, are really necessary aboard commercial planes?

One? None?

Advances in sensor technology, computing and artificial intelligence are making human pilots less necessary than ever in the cockpit. Already, government agencies are experimenting with replacing the co-pilot, perhaps even both pilots on cargo planes, with robots or remote operators.

“The industry is starting to come out and say we are willing to put our R&D money into that,” said Parimal Kopardekar, manager of the safe autonomous system operations project at NASA’s Ames Research Center.

This Centaur Optionally Piloted Aircraft can be
operated unmanned or with pilots on board.

In 2014, airlines carried 838.4 million passengers on more than 8.5 million flights. Commercial aviation is already heavily automated. Modern aircraft are generally flown by a computer autopilot that tracks its position using motion sensors and dead reckoning, corrected as necessary by GPS. Software systems are also used to land commercial aircraft.  

In a recent survey of airline pilots, those operating Boeing 777s reported that they spent just seven minutes manually piloting their planes in a typical flight. Pilots operating Airbus planes spent half that time.

And commercial planes are becoming smarter all the time. “An Airbus airliner knows enough not to fly into a mountain,” said David Mindell, a Massachusetts Institute of Technology aeronautics and astronautics professor. “It has a warning system that tells a pilot. But it doesn’t take over.”  

Such a system could take over, if permitted. Already, the Pentagon has deployed automated piloting software in F-16 fighter jets. The Auto Collision Ground Avoidance System reportedly saved a plane and pilot in November during a combat mission against Islamic State forces.

The Pentagon has invested heavily in robot aircraft. As of 2013, there were more than 11,000 drones in the military arsenal. But drones are almost always remotely piloted, rather than autonomous. Indeed, more than 150 humans are involved in the average combat mission flown by a drone.  

This summer, the Defense Advanced Research Projects Agency, the Pentagon research organization, will take the next step in plane automation with the Aircrew Labor In-Cockpit Automation System, or Alias. Sometime this year, the agency will begin flight testing a robot that can be quickly installed in the right seat of military aircraft to act as the co-pilot. The portable onboard robot will be able to speak, listen, manipulate flight controls and read instruments.

The machine, a bit like R2D2, will have many of the skills of a human pilot, including the ability to land the plane and to take off. It will assist the human pilot on routine flights and be able to take over the flight in emergency situations.  

A number of aerospace companies and universities, in three competing teams, are working with Darpa to develop the robot. The agency plans for the robot co-pilot to be “visually aware” in the cockpit and to be able to control the aircraft by manipulating equipment built for human hands, such as the pilot’s yoke and pedals, as well as the various knobs, toggles and buttons.

Ideally, the robots will rely on voice recognition technologies and speech synthesis to communicate with human pilots and flight controllers.

“This is really about how we can foster a new kind of automation structured around augmenting the human,” said Daniel Patt, a program manager in Darpa’s Tactical Technology Office.

NASA is exploring a related possibility: moving the co-pilot out of the cockpit on commercial flights, and instead using a single remote operator to serve as co-pilot for multiple aircraft.

In this scenario, a ground controller might operate as a dispatcher managing a dozen or more flights simultaneously. It would be possible for the ground controller to “beam” into individual planes when needed and to land a plane remotely in the event that the pilot became incapacitated — or worse.

What the Germanwings crash “has done has elevated the question of should there or not be ways to externally control commercial aircraft,” said Mary Cummings, the director of the Humans and Autonomy Laboratory at Duke University and a former Navy F-18 pilot, who is a researcher on the Darpa project.

“Could we have a single-pilot aircraft with the ability to remotely control the aircraft from the ground that is safer than today’s systems? The answer is yes.”

NASA would like to see fewer humans guiding planes on the ground, too. This month, in a research laboratory here, agency officials ran a simulation of new software intended to bring more automation to the nation’s air traffic control system, specifically to help with congestion and spacing of aircraft.  

Last month at the NASA Ames facility, retired air traffic controllers and commercial pilots sat at air traffic control terminals and helped scientists test the system as it simulated air traffic arriving in Phoenix.

The software, known as Terminal Sequencing and Spacing, can coordinate the speed and separation of hundreds of aircraft simultaneously to improve the flow of planes landing at airports. Ultimately, NASA says, it may be able to increase the density of air traffic in the nation’s skies by as much as 20 percent — with fewer human controllers.

Indeed, the potential savings from the move to more autonomous aircraft and air traffic control systems is enormous. In 2007, a research report for NASA estimated that the labor costs related to the co-pilot position alone in the world’s passenger aircraft amounted to billions of dollars annually.

Automating that job may save money. But will passengers ever set foot on plane piloted by robots, or humans thousands of miles from the cockpit?

“You need humans where you have humans,” said Dr. Cummings. “If you have a bunch of humans on an aircraft, you’re going to need a Captain Kirk on the plane. I don’t ever see commercial transportation going over to drones.”

In written testimony submitted to the Senate last month, the Air Line Pilots Association warned, “It is vitally important that the pressure to capitalize on the technology not lead to an incomplete safety analysis of the aircraft and operations.”

The association defended the unique skills of a human pilot: “A pilot on board an aircraft can see, feel, smell or hear many indications of an impending problem and begin to formulate a course of action before even sophisticated sensors and indicators provide positive indications of trouble.”

Even at NASA’s recent symposium, experts worried over the deployment of increasingly autonomous systems. Not all of the scientists and engineers who attended believe that increasingly sophisticated planes will always be safer planes.

“Technology can have costs of its own,” said Amy Pritchett, an associate professor of aerospace engineering at the Georgia Institute of Technology. “If you put more technology in the cockpit, you have more technology that can fail.”

VASIMR Magnetic Plasma Rocket Could Send Humans To Mars In Just 39 Days

As reported by HuffPost Science: A new type of rocket that could send humans to Mars in less than six weeks instead of six months or longer may be one step closer to reality.  

NASA has selected Texas-based Ad Astra Rocket Company for a round of funding to help develop the Variable Specific Impulse Magnetoplasma Rocket, or VASIMR. The new rocket uses plasma and magnets, not to lift spacecraft into orbit but to propel them further and faster once they've escaped the planet's atmosphere.

“It is a rocket like no other rocket that you might have seen in the past. It is a plasma rocket," Dr. Franklin Chang-Díaz, a former shuttle astronaut and CEO of Ad Astra said in a video describing the rocket. "The VASIMR engine is not used for launching things into space or landing them back but rather it is used for things already there. We call this ‘in-space propulsion.'"  

While missions near Earth would be able to use solar energy to power the rocket, a mission to Mars would require something far more powerful -- most likely nuclear power, which the company has called "an ideal power source in space."  

In ideal conditions, the rocket could propel a spacecraft to Mars in just 39 days.  

So far, a non-nuclear prototype has been able to fire for less than a minute at a time:

The NASA contract, worth about $10 million over three years, would go toward creating a prototype that could operate at high power for a minimum of 100 hours, the company said in a news release.  

The project is being funded as part of the space agency's Next Space Technologies for Exploration Partnerships program. The goal is for the prototype to reach a technology readiness level (TRL) greater than 5 on NASA's 9-level scale.

A level 5 is described by NASA as:

TRL 5 System/subsystem/component validation in relevant environment: Thorough testing of prototyping in representative environment. Basic technology elements integrated with reasonably realistic supporting elements. Prototyping implementations conform to target environment and interfaces.

“We are thrilled by this announcement and proud to be joining forces with NASA in the final steps of the technology maturation,” Chang-Diaz, who took part in seven shuttle missions, said in a news release. “We look forward to a very successful partnership as we jointly advance the technology to flight readiness."  

An image provided by the company shows a schematic view of the VASIMR:

Critics have called VASIMR unrealistic, with Mars Society president Robert Zubrin saying last year that to bring humans to Mars, the rocket would need "nuclear electric power systems with 10,000 times the power and 1/100th the mass per unit power as any that have ever been built."

Megawatt All-Electric Race Car to Compete at Pikes Peak

As reported by Electric Autosport: Drive eO announces the arrival of eO PP03, world’s first one megawatt all-electric race car. Designed and built in Latvia, the 1020 kW (1368 hp) powerful vehicle is to compete at the annual Pikes Peak International Hill Climb in the United States of America on June 28, 2015. “We want to become the first overall winner with an electric vehicle,” said Kristaps Dambis, project director at Drive eO.  

Drive eO is an engineering company specialized in the design and manufacture of electric and hybrid electric prototype vehicles. The eO PP03 is a result of years of development. The Latvian based company was the first to enter and complete the demanding Dakar Rally with a hybrid electric vehicle. This project was followed by the creation of eO PP01, a purpose built fully electric prototype race car to participate at the Pikes Peak International Hill Climb competition. Last year, they were the first to enter this race with a modified Tesla Roadster.

The newly created all-wheel drive eO PP03 has a 50 kWh lithium-ion battery pack and is propelled by six YASA-400 electric motors with in-house developed eO controllers. This package provides a peak power of an impressive 1020 kW, peak torque of 2160 Nm and could reach 260 km/h. The kerb weight is targeted at just 1200 kg.

Pikes Peak International Hill Climb is the second oldest motor racing event in the United States of America. The race is run on a challenging twenty-kilometer (12.42 mile) course with 156 turns. It begins at 2,792 meter (9,160 feet) and finishes at the 4,301 meter (14,110 feet) summit of the Pikes Peak mountain in Colorado Springs.

Kristaps Dambis, project director at Drive eO, said: “We are hugely excited about building world’s first one megawatt electric race car. We have built the car from the ground up and the majority of the components and design has been constructed in-house. We know that racing with a state-of-the-art vehicle comes along with new challenges, but we are well prepared after our Dakar Rally adventure and the two previous times we participated in the race at Pikes Peak. With great pride we’ll soon present the vehicle to the public and hopefully it will surprise everyone. Winning the event is our goal.”

The eO PP03 is currently being assembled at the workshop in Ogresgala Pagasts, near Latvia’s capital city Riga, and is expected to undergo first testing in May. The experienced driver piloting the one megawatt electric race car will be announced in April. The race takes place on Sunday, June 28, 2015 in Colorado Springs, USA.

eO PP03 technical specifications:

• All wheel drive
• Six YASA-400 electric motors with eO controllers
• Peak power 1020 kW / peak torque 2160 Nm
• 50 kWh lithium-ion battery pack with BMS
• Single reduction gear / limited slip axle differentials
• Steel tubular spaceframe with carbon fibre body
• Electrically assisted power steering
• 4-way adjustable shock absorbers
• Ventilated brake discs Ø378 mm front / Ø330 mm rear
• 320/710 R18 slick tyres / 13” × 18” wheels
• Kerb weight: 1200 kg
• Top speed: 260 km/h