Category Archives: Telecommunications Industry

Everything You Need to Know About the SMA Connector

SMA Connector for RF Signals

The SMA connector is an incredible workhorse, offering a wide variety of applications from which it can provide the perfect solution. Because of its versatility, the SMA connector is used in every industry from telecommunications to medical. In today’s spotlight series, we’ll hone in on the venerable SMA RF connector, which provides a critical function in today’s cutting edge medical devices.

What is an SMA connector?

First off, SMA stands for sub-miniature type A. Subminiature connectors are small, hence the name, and are useful in high-frequency applications. This is because SMA connectors are able to provide a steady broadband connection from the KHz range on up to 18 GHz. The inherent reliability of the SMA connector is achieved from a constant impedance of 50 ohms and also because of its low reflection. Electrical impedance is simply a measure used to find the level of opposition that gets applied to a current inside a circuit when the voltage gets applied to it. 50 ohms is considered a good middle ground in the realm of standard characteristic impedance. 

SMA connectors can achieve low reflection and good attenuation because of their shape, which helps to maintain a uniform connection contact. The SMA is coaxial, with the characteristic screw-type coupler; however, these should not be confused with standard coaxial hooking up a home’s cable or internet. To hook up an SMA to a coax requires a special adapter. 

Standard SMA Connector Specs Snapshot:

  • Utilizes a one-quarter inch and 36 thread type coupler
  • Male SMA connectors use a five-sixteenths inch hex nut. This allows the application of torque by a standard one-half inch wrench. The applied torque can be used to easily tighten or loosen the connector.
  • Female SMA connectors utilize a thread for coupling that is 4.32 millimeters long.
  • Employs a special silicon rubber O-ring. This helps to provide separation between the body and the coupler which in turn creates a barrier to outside environmental factors like dust.

Even within a specialized connector like the SMA, there are several different types. Next up, we’ll focus on a Meridian specialty, the SMA RF connector, which provides the crucial connection many different devices in the medical industry rely on to run effectively.

How SMA RF Connectors Help Medical Breakthroughs Happen

RF stands for radio frequency and applies to a range of coaxial electrical connectors. The SMA is one of the most used of the RF-type connectors. Because of the screw-type coupler, the SMA is sturdy mechanically and offers durable performance throughout the life of the system – really important considerations for life-saving medical devices. 

SMA RF connectors come in a male and female variety to provide the crucial connections high frequency medical devices need to consistently send and receive power and data. Male SMA connectors are easily recognizable because they resemble a standard coaxial connection with a center pin inside of its threaded barrel. The female connector acts more like a sleeve which helps provide a good, sturdy connection between the types. Female connectors are usually affixed to a stable device and the male is then used in a removable wire connection for the greatest flexibility within the electrical system.

The sturdiness of construction, extremely reliable performance, and how it fits perfectly into the electrical system is what makes the SMA RF connector the go-to for fields with complex requirements like the medical industry. We produce tens of thousands of SMA RF connectors for medical devices each year. Designing and producing each to exacting standards, we are able to power the devices medical staff rely on to diagnose and treat patients every day. 

Designing the Perfect SMA RF Connector

SMA RF connectors can range from a single connector, customized to provide the perfect connection in an existing system, to a custom cable assembly that provides multiple SMA connections and adapters for providing the greatest range of application. Many SMA RF connectors available today utilize a right angle design but there are also straight angle designs available, all depending on the circuit. Right angle design is a popular choice because it helps maintain the impedance we discussed earlier at a standard level. 

Meridian’s gifted engineering and design team has to calculate the dimensions and structural components of the connection to incredible preciseness. Further, our production team must be absolutely flawless in their assembly, with special attention to the soldering. Too much soldering can lead to what’s known as an impedance mismatch. Impedance mismatch can also occur when the dimensions aren’t exactly right, a mechanical failure, or even when too much air surrounds the contact within the connection. 

Imagine if any of these were to occur during a risky surgery, where hospital staff is dependent upon the many medical devices around them utilizing SMA RF connectors. 

Different Ways to Mount SMA Connectors

  • Panel Mount: this is a female mount made for tough conditions like in the military and industrial settings. With a two-hole or four-hole configuration, panel mounts are easily applied to instrumentation and wireless infrastructure.
  • Bulkhead Mount: female mount with a thread length that is usually longer than the typical 4.3 millimeters to more easily attach to a wall or panel using a nut and washer.
  • Through-Hole Mount: can be vertical or 90 degrees and comes in non-magnetic varieties that are used often in the medical field.
  • Edge Mount: vertical mount that comes in both a standard and drop in variety. 

Losing signal or power mid-procedure isn’t an option which is why our clients have come to know they can depend on Meridian for a quality product that is designed to function as intended cycle-after-cycle.

Does UL-certification matter with SMA RF Connectors?

Creating a product for a device that literally can mean life and death for a patient is a matter no custom cable manufacturer should ever take lightly. We’ve already seen where small deficiencies in the connection can lead to catastrophic failure. This is one of the many reasons we utilize UL-certified components in all of our products, including the SMA RF connector. 

UL-certified components have been tested and verified for their structural integrity, durability, and overall functionality. This allows our design team to utilize components that have known and very specific operating ranges. In this way, we can piece together the perfect amalgamation for even the most complex custom cable assembly

Meridian is proud to utilize UL-certified components and to maintain status as a UL-approved manufacturing facility, having met the stringent quality assurance and quality control (QAQC) requirements of Underwriters Laboratories (UL). We also are proud to have had and continue to maintain our certification as ISO 9001:2015. This difficult to achieve certification requires demonstrable and exceedingly high QA/QC programs that focus not just on quality of the product, but of the entire process – which includes cradle to grave design, sourcing, prototyping, mass assembly, testing, but also emphasizes customer service/satisfaction. 

Making an SMA RF Connector That Performs Flawlessly in its Application

Impedance matching is a crucial step with custom SMA connectors. The design and test teams of Meridian rely on decades of experience in custom cable manufacturing to select the perfect SMA connector to do the job, in the environment, and in conjunction with the other elements of the system – especially terminations. These different components all must work in perfect harmony for the electrical system to perform as it should. 

To produce a one-of-a-kind solution that works perfectly in its intended environment, we are fanatical in our approach to quality. As discussed, quality starts with the very first client contact, through every step of the design and manufacturing process, and then beyond with an industry-leading product warranty. We test each and every product that rolls off our assembly line so that our clients know the product they receive will perform under their exact specifications. 

How do you test SMA RF connectors?

It is indeed rare to go from design straight to volume production without many periods of testing and prototyping in between. Prototyping allows our design team to test several different configurations of the same SMA RF connectors in harsh real world conditions. Often these are even tougher than the actual circumstances the system will face every day. We call this our “advanced life testing lab” which subjects the components to all manner of freezing temps, scorching heat, salt, and other environmental factors that need to be mitigated against during the design phase. 

Aiming for as close to perfection as humanly possible, we also employ highly accurate, automated Cirrus testers. However, there are times such as when the product is entirely unique, that we must design a correspondingly unique and entirely-custom testing unit to ensure the component’s functionality, structural integrity, and above all, safety. 

How to Get a Custom SMA RF Connector Project Started

When you need the perfect solution for a medical device requiring a SMA RF connector, our team is readily available to complete the project on-time and on-budget. Our design managers work with you to understand all of the complexities surrounding your project, set production milestones, lock out the appropriate tools from our massive tool crib, and manage the entire process to ensure the product is made to your absolute satisfaction. Contact us today to go over your specs and outline your options with our dedicated sales team.

Coiled Cable Life Testing

Coiled Cable Life Testing

coiled cords life testing

Coiled cables are used by many industries, medical, industrial controls, aerospace, public safety and telecommunications. Regardless of the industry coil cords are used because they extend. This ability to extend allows a coiled cord allows connections between devices where one device or the other moves. Having the ability to extend means coiled cables are much better solutions in dynamic applications than a fixed wire harness, which can fail easily in these environments.

Since coil cords are a dynamic component in any system testing their ability to withstand repeated extensions and retractions is critical. Meridian Cable, a leading coiled cable designer and manufacturer, has been designing, manufacturing and testing coiled cords for over 30 years. Recently we designed, manufactured and tested a 23 gauge, 7 conductor, polyurethane jacketed, medical coiled cord for repetitive extension fatigue.

The cable used to make the coiled cord tested was designed by Meridian Cable with the following elements.

  • The 23 gauge conductors were each composed of 21 strands of tinned copper with each strand having a diameter of 0.127mm.
  • Each wire was insulated with polypropylene and had an outside diameter of 1.28mm.
  • Finally 7 conductors of 23 gauge each were bundled together and polyurethane was extruded over the bundle.

The raw cable was then made into a coiled cable. To see a video of this process go to our coiled cable video at Meridian Cable’s YouTube channel. To make a coil cord the raw cable is wrapped around a metal rod, put in an oven for heat treating and then removed from the rod.

Once the coil cords were complete Meridian Cable tested them using our custom testing machine that extends and retracts the cable continuously. The electrical and mechanical integrity of each unit is monitored continuously too to determine the exact point of failure. Also, after a set number of cycles the coiled cable is removed from the test machine and its new state is measured and compared to its original mechanical specifications.

The testing process is quite simple actually, but does require custom equipment. The coiled cables are attached to a machine with two arms. One arm is fixed and the other moves up and down. Meridian Cable has several of these machines since we make coil cords with extension lengths from a few inches to over 30 feet! Each cable is connected to electrical test equipment to determine the exact moment any failure occurs. If a failure happens then the test is automatically stopped. The test equipment has a counter to count each cycle, so when that machine stops we know the precise number of extensions and retractions the coiled cable has experienced.

This medical coiled cable passed 400,000 cycles without failure! As you can imagine and medical coil cord or cable assembly must be able to function without failure, and this coil cord designed and manufactured by Meridian Cable exceeded specification by over 4 times! While wire harnesses are great, certain applications demand a cable that can extend and retract, without failure. And as our data is proving we make a coiled cable that can live up to a demanding environment.

Should you need a standard coiled cable or a custom design coil cord Meridian Cable can help. Meridian Cable has over 30 years of experience designing and manufacturing coil cords, coiled cables and cable assemblies. Designed – Built – Delivered, Meridian Cable is ready to help create a solution for you.

Molded Cables: What You Need To Know

Molded Cables: The Facts

Molded cables are extremely important but are rarely noticed by those using them. According to Meridian Cable’s owner and resident molded cable assemblies expert Bud Kinzalow, though they can be small, these cables serve large and important purposes.

Molded cables derive their name from the fact that plastic is typically molded onto cable, and their purpose is to mechanically attach connectors to cables. Kinzalow notes that custom molded cables are created through a specialized process that allows for maximum protection of important parts. “First,” he says, “the connectors are attached to the cable and are subsequently placed into a mold. Next, the mold is closed and the plastic is injected into the cavity that surrounds the cable terminal or connector interface.”

What results from this process are quality molded cables that can stand the test of time. Kinzalow adds, “People use these protective molded cables every day when they grip the plastic on their headphone jacks, plug something into the computer or plug a power cable into the wall.” Created to protect the connection between wires and connectors, molded cables have become ubiquitous not only in the wire and cable industry but also in everyday life. People are able to charge their computers, listen to music and perform other everyday tasks thanks to molded cable assemblies.

Molded Cables: Typical Uses

One purpose that custom molded cables serve is protection of connectors and cables from the elements. According to Kinzalow, “In years past- and still sometimes today – many connections between wires and connectors were soldered, meaning they were welded at a low temperature and one metal was used to hold together two other dissimilar metals. The resulting soldered connection often needed to be covered so that water, other pieces of metal or environmental elements couldn’t damage or short the connection between the wire and the connector. The over-molding was likely created to provide this protection and ensure a longer lifespan for the soldered cable.”

These days, molded cables are rendered to fit varying types of connectors and serve many different purposes. These numerous everyday uses emphasize the importance, in today’s technologically advanced world, of molded cables. You can find molded cables in:

  • Stereos
  • Headphones
  • Computer chargers
  • Cell phone chargers
  • Power cords
  • USB cables
  • Many more everyday devices

Molded Cables: Who Makes Them?

Since molded cables have so many uses, there are numerous manufacturers that can create them to suit varying situations. These manufacturers may turn to custom cable assembly companies like Meridian Cable to design and create custom molded cables for them.

“Original Equipment Manufacturers (OEMs) looking to design and sell molded cables should ensure that the vendor that they turn to is UL, ISO, FDA and even military cage code certified,” Kinzalow advises. For example, if an OEM turns to Meridian Cable to build custom molded cables, they will find that Kinzalow’s company has all the necessary certifications in addition to the design expertise to be able to create a design that is unique to each OEM’s performance specifications. “Also important,” he adds, “is having the manufacturing wherewithal to make the product that the customer needs, the logistics capability to deliver the molded cables anywhere in the world, and the integrity to follow through on what was promised.”

It is extremely important to trust the vendor who is designing and making the cables because, though these molded cables can be small and seemingly easy to make, there is in fact a great deal of work that goes into creating perfectly fitted and useful molded cables.

Molded Cables: Who To Contact

If you are an Original Equipment Manufacturer looking for custom molded cables, contact Meridian Cable (www.meridiancable.com) for service from a UL approved manufacturing facility and UL approved distributor of over 50 different types of wire and cable. Meridian Cable is also ISO 9001:2008, cage code and FDA certified. Call us at 1-866-866-0544 to speak with one of our designers and discuss how we can meet your performance specifications for custom molded cable assemblies or view some of our molded component designs.