The Neverending Quest For Size Reduction
As with most technologies, RF and Wireless system design is an ever-changing and shifting world. As certain technologies or RF bands become popular, others fade away.
However, the one ever-present force on the industry is the steady, but relentless, push towards smaller size and better integration over time.
Lightning/Surge Protection at the PCB Level?
Here at NexTek we understand the desire to bring things into the box, or even all the way onto the Radio PCB… However, we also know that Lightning Transients contain too much energy to deal with safely at the PCB Level… Trace widths, ground place areas, and the components themselves all become limiting factors that will prevent complete and effective protection.
Given this reality, the last place where it is reasonable and safe to protect against Lightning or other Surge events is at the radio’s box or chassis level. By replacing the normal I/O connector with a protected version, designer can ensure that they have high-performance protection without paying any significant size or weight penalty. As long as the radio’s chassis is grounded well, the bulk of the Transient Energy will be drained safely to ground before entering the box and/or the PCB itself.
It may still be advisable to install some simple protection on the PCB, but only for final clean-up…Something like a small Protection Diode coupled with a DC Blocking Capacitor (if possible for your application) would provide plenty of protection against any residual energy that gets past the Protected I/O Connector.
Maximum Protection in the Minimum Amount of Space
Below, you can see an array of our Ultra-Compact protection options… They all include high-performance lightning protection, and are available in a wide variety of connector configurations on both the Input and Output side.
Outside Connector Options – Type N, TNC, SMA
Inside Connector Options – SMA, MMCX, RG188, RG316, and more!
Threat Types – Lightning, Static (ESD), and EMP
You Might Not Know; Just as our line of Power Filters are used to provide EMC compliance for a wide variety of military and government applications, our line of Surge Arrestors for coaxial RF lines are also in-use on an wide range of systems worldwide!
Whether they are installed on a Permanent Installation or a Land Vehicle, Ship, or Airborne Vehicle… Our surge arrestors provide the type of rugged performance and long lifetime that any Military or Government user demands. Solutions range from standard off-the-shelf units all the way to fully-custom solutions developed to meet a complex or special set of requirements.
We can provide protection against any threat type, including;
With the proliferation and continued growth of the use of Radios and Radio-based technology (sensors like radar, communications, even electronic warfare [EW]) across all military equipment and systems, there are a growing number of requirements for Lightning and Surge protection to ensure that mission-critical equipment and capabilities remain up and working properly at all times!
In fact, NexTek was formed as an EMC engineering consultant outfit, and our first contracts ever were in the Military world. With this type of experience and pedigree, you can be confident that your NexTek arrestor will provide protection, performance, and trouble-free operation…whether you are using it in a Mil/Gov application or not!
Available with SMA and TNC connectors, our G-Class arrestors (The PTCSAFSAF20G and the PTCTNFSAF20G, for example) cover a wider RF Band than any other coaxial protection design in the world. Because of the exceptional wideband performance from DC all the way up to 11 or 12.5GHz, there is no arrestor available today that will cover the same number of potential applications. When the wideband ratings are combined with the extremely small form factor of these units, there is truly no other arrestor out there which can come close.
These units are perfect for retrofit or other installations where space is at a premium, or those who simply want a high quality protector that takes up minimal space! In fact, these fully featured lightning arrestors barely take up any more space than a typical connector feedthru that contains no protection at all!
Also, keep in mind that like all NexTek solutions….
- All G-Class arrestors are Designed, Engineered, Assembled, and Tested here in the United States!
- This design incorporates 30 Years of Experience and Expertise into every feature and detail.
- They are truly High Quality Advanced Designs, ready for the most demanding applications.
PTCSAFSAF20G – SMA to SMA, DC to 12.5GHz
PTCTNFSAF20G – TNC to SMA, DC to 11GHz
How do I select the proper coaxial surge protector for my application? What are the primary criterion I should pay attention to when comparing different lightning arrestors? This post will review the fundamentals of coaxial arrestor product selection and also provide links to some helpful Articles and Tools to help you learn more about the process and eventually make your own selections!
There are really only four primary selection criteria, with a fifth line below to account for any other requirements.
RF Performance – Your Frequency of Use and RF Power Level
During >99% of a coaxial arrestor’s life, it is operating as a totally passive connector. Therefore, RF Performance ratings are the only specs that matter during this time!
Connector Type – Your desired connector type and gender configuration.
In order to ensure the best compatibility with the system they will be used in, it is best to match connector types to minimize the use of adapters.
Surge Response and Performance – Your Surge/Lightning Requirements or Susceptibility Levels
These can be specific and give a detailed Threat Level to test against along with an accompanying residual energy Test Limit, or it can be as broad as “I know I need protection.”
DC Pass Required? – Will you be sending DC Power along the coaxial cable with the RF energy?
This is an important detail, as some arrestors are not capable of passing DC Power!
Miscellaneous Requirements – Any additional requirements with a high priority or importance?
Are there any additional (secondary) requirements that could influence the proper product choice? These could be related to Environmental, SWaP, Lifetime Ratings, Dimensions, or others!
Learn more about the selection criteria above by following the links below… There is a full-length article about Selecting Coaxial Lightning Protectors and two useful links to other pages on nextek.com with even more product selection info!
As always, don’t forget to Contact Us with any questions, comments, or requests for selection assistance!
Other Arrestor Selection Process Resources
We have added NexTek’s new coaxial arrestor product to the website and product selection tool, and you can now find information about all four variations!
The PTI series provides effective protection in an extremely compact form factor, and includes a series capacitor to block DC energy and further reduce the amount of energy that gets past and flows into the radio being protected. This series capacitor guarantees effective protection from the Gas Discharge Tube front-end by eliminating the need to rely on or coordinate with the output-side capacitor of your radio.
Available with a TNC (f) bulkhead and SMA (f) connectors, in a range of RF pass band and RF Power ratings. See below and explore the datasheets to learn additional details!
- Excellent Response and Residual Energy Reduction
- Compact TNC to SMA Bulkhead Protector
- Low VSWR and Insertion Loss
- Multi-strike, Rugged and Waterproof
Product Page Links:
Today’s post highlights a type of Transient Threat that NexTek arrestors provide protection against. Although Lightning energy is the primary source of damage to coaxial lines and systems where they are used, there are also other types of Surge Energy that can cause damage to electronics.
ESD, or Electro-Static-Discharge, discharges can reach many kilovolts in potential and therefore could cause significant damage to most unprotected electronic equipment. Although the total energy contained within an ESD discharge is relatively low, it is the fast risetime and kilovolt+ voltage potential that are the main causes of damage.
For any application or system which uses coaxial transmission cables and connectors, there is likely to be some risk of direct human contact to an “exposed” (i.e. un-mated) coaxial center pin which in-turn makes ESD discharges directly onto the center pin quite likely. In this case, protection must be installed or afforded in order to ensure the continued performance of a given system or piece of equipment.
When examining a specific application and quantifying the ESD threat level, there are two main paths to travel down: One, the ESD threat may be given by a specific Industry Standard document (MIL-STD, IEC, IEEE, EN, etc) according to a judgement made upstream in the overall program…or an approximate threat level or desired protection level based on the program-level design requirements.
See below for a table which lists some ESD Requirements which may apply:
Standards that require ESD testing include:
- ISO 10605
- Ford EMC
- ISO/EN 61000-4-2 needed for the CE mark
- IEC 61000-4-2
- ISO TR10605
- RTCA DO 160
Learn More about NexTek’s Coaxial Surge Arrestors here: Coaxial Surge Arrestors
NexTek’s portfolio of available Coaxial Surge Arrestors contains one design that is uniquely suited for High RF Power radio applications. With Protection Voltage Ratings of up to 3500V and RF Power Ratings of up to 30kW+, the PTR7AF7AFxxK1 is uniquely suited to provide Lightning Protection for High RF Power installations.
The availability of 1400, 2500, and 3500V ratings mean that there is a specific configuration available to suit any RF Power level. Most coaxial Lightning Arrestors are available with ratings up to 800 or 1000Vdc and have Type N connectors as the largest available option, while the PTR7AF7AFxxK1 uses the following unique design features:
High Power Capable 7/16 DIN (female) connectors
High Power Capable Thru-Path Geometry which meets or exceeds 7/16 DIN RF Power ratings
High Voltage GDTs (1400V, 2500V, 3500V)
Multiple Gas Discharge Tubes (5 per arrestor) for a Long Lifetime
Replaceable Gas Discharge Tubes to allow periodic service or repair (as needed)
Don’t settle for Spark Gap protection for lightning & surge protection of your High Power Broadcast system. Old-school solutions like “spark gaps” can have Residual Voltage peaks of 10kV+, which can be enough transient energy to damage radio and amplifier outputs!
Instead, select the proper Protection Voltage based on your application details… then select the Protection Voltage which will allow normal radio operation and broadcasting, but is also low enough to turn-on quickly and limit Transient energy as much as possible during a lightning strike.
High RF Power Coaxial Arrestor – DC to 1GHz – Multiple Gas Discharge Tubes
For more information on how to make the appropriate calculations and select a Coaxial RF Lightning Protector; See the PTR7AF7AFxxK1 Product Datasheet for additional information, as well as a NexTek Technical Article published in Microwave Product Digest in 2011 entitled “Lightning Protection for High RF Power Applications.”