RF Cafe Software
About RF Cafe
1996 - 2016
BSEE - KB3UON
RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...
All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.
My Hobby Website:
Try Using SEARCH
to Find What You Need.
There are 1,000s of Pages Indexed on RF Cafe !
Anatech Electronics, a manufacturer of RF and microwave filters, has published its March 2016 newsletter. As always, it includes both company news and some tidbits about relevant industry happenings. This month, Sam Benzacar's main thesis addresses the ineptitude of big city planners when it comes to wireless communications. He notes how NY City, in updating its archaic analog emergency and public service radio system, has chosen the TETRA system which is not compatible with FCC recommended Project 25 standards (includes new 700 MHz public safety band). Sam won't say it but I will - follow the money from city coffers to the chosen system contractor and you will probably learn why a TETRA system is being installed. Fortunately for Big Apple occupants, Ham radio operators are standing by once again to save NYC during the next big disaster.
By Sam Benzacar
In the Big Apple, one might expect that after 9/11, the city would have gotten its act together, quickly, to solve issues of incompatible radio networks, interference, and other problems that stymied efforts of various agencies to communicate. To its credit, major changes have been made to remedy some of these issues. However, it came to light recently that the Metropolitan Transit Authority (MTA) announced it was moving its city bus radio system to the same frequencies at 700 MHz as used by the New York Fire Department and EMS, even though the FCC warned about possible interference with first responders.
The MTA, after using the same archaic analog system it had for the last quarter century, is finally modernizing its network, which operates outside of public safety frequencies. In addition to being easy to listen to even with a cheap scanner, it was no doubt easy to jam, although I can't find any record of that happening.
Not only this, but the MTA chose to use TETRA rather than adhere to Project 25, which embodies widely-accepted standards designed to ensure that federal, state, and municipal public safety agencies can communicate with each other. TETRA is not compatible with Project 25. Granted, the MTA is not a public safety agency but in a crisis situation it may as well be. The FCC in fact stated in 2012 that it opposed the use of TETRA on public-safety frequencies owing to its incompatibility and "would therefore undermine public-safety interoperability," further stating that it "will not allow TETRA technology to operate in 700-megahertz public safety spectrum."
The five-year contact, potentially worth $202 million including 8,500 radios for buses, was inked with Parsons Transportation. There was the usual protest from Motorola, which lost out to Parsons and protested to the MTA that "if this system is deployed without FCC approval and creates any interference issues for public-safety radio users in New York City, the problems could be catastrophic." You'd think that the MTA might have taken notice of the NJ Transit state-wide system upgrade, which is two years late in "going live" owing to similar issues with the FCC.
This isn't the only other communications problem the city has been wrangling with either, as NYPD just announced that it is implementing its new radio network that allows police to communicate while underground, such as in subways. Before this, incredibly enough, the radios used by transit police officers operated on different frequencies than those at street level. At least the city seems to be making progress of sorts, but incompatible radios may very likely interfere with public safety radios, a situation similar to many of those we at Anatech Electronics have encountered year after year. We've solved them with RF and microwave filters, which are still the most effective way to combat interference.
So if you're having interference problems—or anticipate them—you're first call should be to us, at (973) 772-4242. Or send us an email to email@example.com.
Microwave Technology for "Zombie" Potholes
Some potholes just never go away, requiring patch after patch, but a new approach using microwave energy may be the answer. Researchers at the Natural Resources Research Institute of the University of Minnesota have completed a study to evaluate pothole repair tactics using iron oxide mineral magnetite (Fe3O4). As magnetite and magnetite-containing rock are excellent absorbers of microwave energy it heats up quickly, so by adding it to patching compound, packing it in a pothole, and blasting it with energy from a 40-kW (presumably magnetron-based) generator for 8 to 12 minutes it to 212o F it softens, essentially becoming part of the surrounding pavement.
The system was built by a company that had previously developed a truck-mounted microwave system to thaw frozen ground to access buried utilities, and adapted it to the project. According to the researchers, such a pothole repair compound can be made almost entirely from cheap, abundant recycled materials that many maintenance departments have on hand.
New GaN-Powered Patriot Ready to Go?
Raytheon's 18-year, $200 million GaN development efforts are about to be revealed, at least briefly, when its new AESA radar for the Patriot missile defense system is demonstrated at the Association of the United States Army (AUSA) show this month. The Patriot currently uses GaAs MMICs but thanks to GaN's benefits in power density (among other things) it ushers in a new era in radar and electronic warfare systems. The US Army and several foreign countries appear interested. Raytheon built a demonstrator that it says will be ready for testing in two years. Other than the AUSA demonstration, it's not likely reporters and other curious parties will see it again soon.
New Ultra-Wideband Sensor Coming
BAE Systems is developing an ultra-wideband sensor for the Navy for rapid detection, identification, and location of RF signal emitters over "all bands and from all directions". The development contract for the Full-Spectrum Staring Receiver was issued by the Office of Naval Research and is worth $11 million. The system is part of ONR's Electronic Warfare Discovery & Invention Program to develop a broad range of next-generation electronic warfare systems that exploit, deceive, or deny enemy use of the spectrum. With this capability, ships could be constantly aware of threat emitters over a very broad frequency range.
5G's Big Challenge: Latency
Among the large number of challenges posed by the fifth generation of cellular, reducing latency is surely the most challenging, according to various reports. The goal is to reach latencies of less than 1 ms, which will be required by vehicle-to-vehicle communications, virtual reality, and other applications. As sub-1 ms latency faces the limits posed by the laws of physics, this will be extraordinarily difficult at best. However, Samsung revealed that it has demonstrated this capability at 60 GHz, a frequency likely to be used at some point after 5G is deployed. At Mobile World Congress, the company transmitted eight Ultra High-Definition 4K videos over the air without delays.
Check out Our Filter Products
About Anatech Electronics
Anatech Electronics, Inc. (AEI) specializes in the design and manufacture of standard and custom RF and microwave filters and other passive components and subsystems employed in commercial, industrial, and aerospace and applications. Products are available from an operating frequency range of 10 kHz to 30 GHz and include cavity, ceramic, crystal, LC, and surface acoustic wave (SAW), as well as power combiners/dividers, duplexers and diplexers, directional couplers, terminations, attenuators, circulators, EMI filters, and lightning arrestors. The company's custom products and capabilities are available at www.anatechelectronics.com.
Anatech Electronics, Inc.
70 Outwater Lane
Garfield, NJ 07026
Posted March 29, 2016