How much do you love your smartphone? Yup, so does Chris Churchill, PORON Cushioning Senior Development Engineer and BMX biker. In this video, he tests PORON® XRD® and it’s ability to absorb up to ninety percent of the force applied* while remaining soft and flexible.

Protect This

This is why PORON XRD is the cushioning material of choice among consumer electronics accessories, sporting goods, and safety work boot brands. It protects valuable iPhones and iPads, not to mention precious body parts from head to toe.

For more interesting videos that will surprise you, visit the PORON Cushioning YouTube Channel. We’d love your feedback, and if you are feeling inspired, to see some of your creative videos testing products with PORON Cushioning Materials.

 *as measured according to ASTM-F1614-C

 

This post authored by John Coonrod originally appeared on the ROG Blog hosted by Microwave Journal.

Dielectric constant (Dk) is a key parameter to consider when choosing a microwave printed-circuit board (PCB). But what microwave circuit designers may not always appreciate is the “choice within a choice” with some PCB materials, or when it might make sense to select a circuit material with a higher Dk value. High-Dk circuit materials can make it possible to miniaturize high-frequency circuits beyond what is possible with lower-Dk circuit materials. Understanding where high-Dk circuit materials fit within an RF/microwave designer’s toolkit can provide engineers with a great deal of flexibility when developing both active and passive high-frequency circuits.

ROG_DkApp_finalSeveral recent blogs took a closer look at the meaning and importance of PCB Dk, without exploring the use of higher-Dk circuit materials. See “Getting the Low Down on Dielectric Constant,” and “Digging Deeper into Dielectric Constant for PCB Materials.” More and more, designers are using higher-Dk circuit materials for active circuits, such as power amplifiers, and passive circuits, such as antennas, for reduced size and to take advantage of some of the other characteristics of high-Dk circuit materials. The dimensions of a circuit to support a particular wavelength/frequency decrease as the Dk of the circuit-board material increases. But using a higher-Dk material in place of a low-Dk material is not just about going smaller, since the electromagnetic (EM) properties of the different materials must also be considered for a given circuit design.

“High” Dk is a relative term, of course, and what is defined as a “high-Dk” circuit material may vary across different circuit-material manufacturers. Since materials with relatively low Dk values are typically used for RF/microwave applications, a Dk value of 6.0 is often used as the lower threshold for high-Dk RF/microwave circuit materials.

Shrinking a circuit, whether active or passive, can help many applications. Using a high-Dk circuit material can also impact the EM wave properties of the circuits on that material by slowing the phase velocities of the EM waves, condensing the electric fields and the power handled by the circuits, improving coupling, and reducing higher-order modes and radiation losses. Of course, higher-Dk circuit materials can also lead to potential issues with dispersion and transmission lines with higher impedance values, which may not always be desired.

Simulations Compare Size Reductions for Different Dk Values

To get a handle on the impact of higher-Dk materials, a number of simulations on different types of circuits were performed with Sonnet Professional EM simulation software from Sonnet Software. The simulations were based on RF/microwave circuit materials of the same thickness, with Dk values of 3.0, 6.5, and 10.8, and they were run for patch antenna radiating elements based on 50-? impedance. The low-Dk material (Dk = 3.0) was used as the reference in terms of antenna radiating element area to achieve a given center frequency, such as 2.5 GHz. The simulation results projected a better than 40% savings in size for the patch antenna element with the Dk = 6.5 material, and a better than 60% reduction in area for the patch antenna element with the Dk = 10.8 circuit material.

As an example of a high-Dk material, RO3210™ laminate from Rogers Corp. is a ceramic-filled PTFE material with a Dk of 10.8. It should be noted that, as these patch antenna elements shrink, the feed lines needed to get signals to and from the antenna elements must also reduce in size (and can suffer higher loss when fabricated on higher-Dk materials), which may require design strategy if the feed lines are fabricated on a separate circuit material than the patch antenna elements.

Miniaturization

Higher-Dk circuit materials can also help miniaturize RF/microwave filters, such as microstrip edge-coupled bandpass filters. To predict the size reductions, the Sonnet simulation software was again employed to simulate two Chebyshev bandpass filters designed with the same criteria, including a 150-MHz bandwidth centered at 2.5 GHz, except that one filter was built on circuit material with Dk of about 3 and the other on circuit material with Dk of around 10.8. The simulations were based on 25-mil-thick (0.635-mm-thick) circuit materials with 0.5-oz. copper. Little time was spent on optimizing the filters, although the simulations were performed with the goal of achieving the same electrical performance for the two filters. The center frequencies and bandwidths were within a few percent of each other. The main difference between the two was about a 37% reduction in PCB area for the filter designed on the Dk = 10.8 material.

Reduction in size can also be important for active circuits, such as power amplifiers, although design considerations when choosing a circuit material can be somewhat different than when sorting through circuit materials for passive components, such as antennas and filters. Microwave power amplifiers have commonly been fabricated on circuit materials with Dk values of 3 to 4, which are materials capable of low insertion loss, a parameter critical for achieving high performance in high-frequency amplifiers. Dramatic size reductions in amplifiers can be achieved by using a circuit material with a higher-Dk value, such as Dk = 6.5, although designers should also be aware of the importance of maintaining low insertion loss when choosing a higher-Dk circuit material for a power amplifier. Another key higher-Dk circuit material property to consider for a power amplifier is thermal conductivity, since any reduction in an amplifier’s size means a higher power density for the amplifier PCB and its associated components, such as heat sinks.

Hybrid Multilayer PCBs

Circuit designers may sometimes find that it is advantageous to fabricate hybrid multilayer PCBs formed with circuit materials of different Dk values. By “customizing” the Dk values of the circuit materials to different portions of a circuit design, such as amplifiers and filters, a certain level of control is achieved over the size of the components in the overall circuit or system. And by working with different circuit materials, each material can be specified for other performance characteristics, such as thermal conductivity or loss, as needed by that part of the circuit. A multilayer PCB can be “tailored” in terms of its choice of materials, with lower-Dk circuit materials used where appropriate and higher-Dk circuit materials serving to miniaturize active and passive circuit functions where needed.

Do you have a design or fabrication question? John Coonrod and Joe Davis are available to help. Log in to the Rogers Technology Support Hub and “Ask an Engineer” today.

 

Change may seem slower in the rail industry as trains have longer lives than many methods of transportation. Yet, as The Economist reports, there is no shortage of new ideas.

Better technologies are delivering everything from improved traction, braking and route-planning to sleek levitating trains designed to glide on air at an astounding 500kph (310mph). Energy-efficiency and safety are up, and derailments are down. There are schemes to transfer electrical energy from braking trains into local power grids, and even more radical plans for “moving platforms” that dock with high-speed trains.

Railway Technology Magazine

Railway Technology Magazine

To grow, a railroad needs to push more volume through a relatively finite network of tracks, locomotives, and railcars. New technology is essential to maximizing throughput; it’s a constant balance between analytics-driven automation and human judgment. With increased throughput and speed come concerns about safety.

Positive Train Control

A 2008 train crash in California in which 25 people died led to the Rail Safety Improvement Act, which mandates that all major US railroads implement a PTC (Positive Train Control) system by December 2015.

PTC deters train wrecks. It combines GPS, track-side devices, wireless radio, and software into a monitoring system for train position and speed. It can slow or stop a train before a collision due to excessive speed (like the 2013 crash in Spain), ignoring a red signal (as in L.A. Metrolink’s 2008 incident), and track incursions (which caused a 2012 accident in Valparaiso, Ind.).

A dozen PTC projects, involving nine railroads in at least 16 states, are in varying stages of development and implementation. The system will cover about 70,000 miles of track when completed. A consortium led by UP, CSX Transportation, Norfolk Southern Railway, and BNSF Railway is leading the interoperability effort. Due to the expensive and complicated nature of PTC technologies, rail companies recently Congress for a five-year extension on the 2015 deadline.

New Crashworthiness Standards in the US

The US Federal Railroad Administration’s (FRA) Railroad Safety Advisory Committee has implemented new “crashworthiness” standards for next generation high-speed passenger rail equipment. According to Progressive Railroading,

The changes establish performance-based requirements for an interoperable rail network, permitting the use of “service proven” designs and advanced technologies, while ensuring a consistent, systematic approach to safety.

The standards provide baseline safety requirements for next-generation rail equipment that travel up to speeds of 220 mph on high-speed track. The standards also provide the flexibility to operate with existing freight- and passenger-rail systems at speeds up to 125 mph.

EURAIL Magazine

EURAIL Magazine

US crashworthiness standards mean Amtrak must use trains with locomotives on both ends. This makes them slower and heavier than bullet trains used in Europe and Asia. The new standards reflect that US passenger trains often share tracks with freight railroads rather than operating on their own lines.

Amtrak reports it is working on a series of new locomotive tests, “including maximum speed runs, acceleration, and braking, operating with Amtrak passenger coach cars attached and testing the overall performance capabilities of the locomotive. Engineers are also validating the on-board computer system and software, as well as evaluate ride quality by using instruments to measure things such as noise and wheel vibrations.”

European Safety Standards

Over the past 12 years, the European Union has pushed to transform national rail systems into a single market. With recent crashes, there is growing public pressure to install the latest automatic braking technology, as well as calls to reverse staff cuts that have left drivers alone and working longer hours that can result in human error.

To enhance safety, the European Train Control System is an automatic train protection system and GSM-based radio system that electronically transmits information from the track to the train to an onboard computer that calculates the maximum permitted speed and that can automatically slow a train. The new system will gradually replace the more than 20 train control systems across the EU.

In addition, EN 45545, the European Fire and Fumes Regulation, is moving from technical specification to implementation. According to EURAIL magazine,

All materials used in/for rail applications, such as seating and claddings (e.g. walls and floors) must meet stringent criteria in terms of flame spread, heat release, opacity, and the toxicity of smoke emitted during a fire. Fire is particularly dangerous in these enclosed spaces because evacuation is complicated and the air quickly becomes unbreathable.

Development continues as railroad companies look to key technologies to increase efficiency, safety, reliability, and provide a better passenger experience.

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Rogers Corporation helps power, protect, and connect our world with greater reliability, efficiency, and performance. Our innovative materials technologies enable transformative megatrends like clean technology, mass transit, and internet connectivity. By delivering solutions for tomorrow’s breakthroughs, we are building a cleaner, safer and more connected world.

 

We are honored to announce that Rogers Corporation has been named one of the top 40 tech companies in Connecticut by the Marcum Tech Top 40.

Screen shot 2013-09-17 at 11.40.44 AMThe annual award, presented by Marcum LLP, one of the largest independent accounting and advisory services firms in the U.S., is given to the top 40 fastest growing technology companies in Connecticut.  Having achieved this accomplishment, Rogers Corporation will be honored with all of the 2013 winning companies on Thursday, September 26 at the Toyota Presents Oakdale Theatre in Wallingford.

The annual award is given based on the percentage revenue growth over the previous four years in six categories: Advanced Manufacturing, Energy/Environmental Technologies, Life Sciences, New Media/Internet/Telecom Technologies, IT Services and Software. To qualify for the Marcum Tech Top 40, companies must have had operating revenues of at least $50,000 in 2009 and $3 million in 2012; be headquartered in Connecticut, and own proprietary technology or proprietary intellectual property that contributes to a significant portion of the company’s revenues, or devotes a significant proportion of revenues to the research and development of technology.

According to Bob Daigle, Rogers’ Chief Technology Officer, the company’s advancements in technology are derived from a culture that nurtures innovation and is backed by sustained investment in research and development.

Said Daigle, “We are pleased to be recognized for the work we do, and for the contributions we are making in multiple categories. It’s an exciting time for Rogers as we are investing in a new Innovation Center and collaborating with leading innovators in materials science to develop new, innovative solutions to create a cleaner, safer, more connected world.”

For more information on the Marcum Tech Top 40 awards, visit the Connecticut Technology Council and Marcum LLP.