Environmental testing is a crucial part of antenna qualification. Depending on which application(s) an antenna is to be used for, the environmental qualification standards for which it has to pass will vary.
JEM Engineering qualifies both our own and our customers’ antenna products in a number of ways, including testing them in at least one of our in-house chambers. Both the Tapered Antenna Test Facility (TATF) and the Spherical Near-Field (SNF) chambers perform a number of measurements at varying frequencies. While these measurements indicate an antenna’s RF capabilities, the antenna is not fully qualified until it is rugged enough for long-term practical use.
Each of JEM’s qualified antennas is a product of a collaborative effort between both electrical and mechanical engineers. For example, the electrical engineer designs the printed circuit boards (PCBs) and various radio frequency components, whereas the mechanical engineer designs the product’s housing, as well as additional internal components that would allow the unit to withstand various environmental conditions. Additionally, the RF test technicians collect quantitative information pertaining to the antenna’s electrical design, while the mechanical engineer must put the unit through rigorous environmental testing, including shock, vibration, heat, immersion, humidity, chemicals, wind, and frost.
There are a number of different standards by which an environmental test may be performed, but because JEM Engineering is a contractor for the United States Department of Defense, we adhere by defense (or “military”) standard, also known as “MIL-SPEC.” While JEM Engineering does not have the capability to perform environmental testing in-house, we work closely with our trusted partners, who handle our required MIL-SPEC tests once we’ve designed and built any necessary fixturing for them.
MIL-SPEC environmental tests are classified by codes. For example, MIL-STD-810 Method 516 measures shock, at values ranging from as low as 20G’s to as high as 75G’s. Similarly, MIL-STD-810 Method 514 denotes a vibration test. Some tests take into account a combination of atmospheric factors. An example of this is MIL-STD-810 Method 520, which involves quantifying the temperature, altitude, humidity, and vibration a product can withstand.
Lastly, for a general overview on what processes are involved in qualifying antennas, you may refer to our blog post, The Makings of a Reliable Antenna.
Over the past 16 years, JEM Engineering has designed and manufactured an extensive product line of antennas, ranging from frequencies between 2 MHz to 40 GHz. We pride ourselves in our ability to not only innovate and create new designs, but also to continue to improve upon existing products. We are committed to not only delivering better performance but also manufacturing them more efficiently and sustainably.
As we discussed in a previous post, before we can manufacture, we must prototype. For this step in the process, we are beginning to explore additive manufacturing, or as it’s more commonly known, 3D printing.
Why additive manufacturing (aka 3D printing)
As the name suggests, additive manufacturing involves successively adding thin layers of material together to form a three-dimensional embodiment of a computer aided design (CAD) model. Traditional manufacturing, on the other hand, is normally subtractive. Again, one may infer that in traditional manufacturing, the material (plastic, metal, fiberglass, etc.) is carved, cut, or hollowed out either by hand or using a machine to form the final structure.
Reducing material waste. While modern technology has vastly improved subtractive manufacturing, it still has its limitations. One of which is the amount of material waste it creates. 3D printed materials are produced according to the specifications of a digital file, such as a CAD (Computer Aided Design) model created using a modeling software. Alternatively, 3D scanners can scan a solid object and the printing machine can reproduce the object’s shape. Both methods allow the machine to create an exact blueprint to print, leaving little to no excess material.
Increased cost-effectiveness. Reducing the cost of materials and labor makes for lower expenses for the rest of the supply chain as well. Manufacturers, not unlike JEM Engineering, must source product components and building materials from qualified vendors. More often than not, there are costly NRE (non-recurring engineering) costs associated with custom components, and in some cases, additional tooling costs whenever previously used tools have worn out. While in the prototyping stage, it is common for there to be a few or even several different revisions made to any single custom component. As one can imagine, such revisions can restart entire processes, including the tooling. More processes = more labor and more materials = more cost. Most importantly, the cost to the manufacturer also drives the cost to the customer.
Faster turnaround. Rapid prototyping is one of the primary applications of 3D printing. The aforementioned tooling processes not only cost money but often take a lot of time, especially if during the course of the prototyping stage, revisions are made. With 3D printing, once a revision is made to the digital model, a new physical model can be printed out almost as quickly. The faster the turnaround time of prototyping and production, the sooner the end user will receive the finished product.
More complexity. Within certain constraints, such as size, there is almost no limit to the complexity of shapes that a 3D printer can produce. With this capability comes more creative freedom and innovation. Also, more objects can be made as a single piece, making it more durable. Imagine a car with a chassis made of one single piece, whereas with traditional manufacturing, it would have been several pieces welded together.
How additive manufacturing will shape antenna design
All factors considered, 3D printing unlocks nearly unlimited possibilities for antenna design. Using this technology, our engineers can design antennas in a larger variety of forms to suit our clients’ needs. Perhaps just as importantly, these custom products can be produced faster and at a better value, without compromising quality and performance.
Every product, specialty or off-the-shelf, must be designed, tested, and perfected by a team of experts, so that the end-user can be assured of its reliability.
The same applies to antenna design.
Our customers trust us to provide them with custom products, many of which have never been made in the past –or even conceptualized.
In this post, we share some of our antenna designing know-how…
1. Knowing where to start. Every single one of our antennas started out as a concept. Either a client or one of our own engineers wanted a device that could deliver a specific result, and our team worked to bring that concept to full-scale production. Our experts find out what the client is looking for, and quickly figure out how to make it happen. Our engineers have several decades of combined experience creating detailed drawings from 2-dimensional drafts to 3-dimensional CAD models.
2. Performing a structural analysis. Naturally, one would want to make sure that the antenna design doesn’t just look good on paper, but it also holds together, at the very least. However, it would be preferable to detect design flaws before spending money on building materials. For instance, COSMOS Static Analysis is an cost-effective way to perform a structural analysis on a computer-generated model, such as a SolidModel. We use this method to assess the feasibility of custom antenna design projects.
3. Developing a prototype. Before one builds the final product, they must create a prototype to not only further evaluate a design, but to also establish the most efficient assembly methods for it, and assess the cost effectiveness of its bill of materials. This also leads us to the next item on the list…
4. Using the right materials. The difference between selecting one material over another can not only mean cost savings, but also overall better performance and longevity. Our mechanical engineers excel at finding the best materials for a project, measurably increasing the practicality of a product.
5. Seeing the prototype in action. So now it’s time to test the prototype. Before the product can go out into the field, it has to perform well in the lab. In our case, the antenna has to be carefully tested in one of our two test chambers by a well-trained and highly-skilled technician, who will provide guidance and support during the test, as well as assist with data analysis and interpretation. In a previous post, we explore antenna qualification in more detail. Read it here.
In summary, designing a functional and structurally sound antenna has many crucial and complicated processes. Luckily, we can help you every step of the way! JEM Engineering staffs a Mechanical Engineering department capable of providing expertise to every antenna design. Send us an inquiry or call us at 301.317.1070 to let us know what you need!
Quality & Customer Service – Our Policy
JEM Engineering exceeds customer expectations by providing custom antenna design, manufacturing and testing solutions with a commitment to comply with customer requirements and continually improve the effectiveness of the quality management system by maintaining a motivated, highly skilled and innovative team, and becoming a leader in our industry. Our commitment to quality is evident as our Quality Management System (QMS) is ISO 9001 Certified.