Antenna Engineering Blog
JEM Engineering is a minority owned company and in honor of Black History Month we would like to shine light on two Black engineers who have made an impact in the world of engineering.
Elijah McCoy was born in Colchester, Ontario, Canada on May 2, 1844. His parents were George and Emillia McCoy, former slaves from Kentucky who escaped through the Underground Railroad. George joined the Canadian Army, fighting in the Rebel War and then raised his family as free Canadian citizens on a 160-acre homestead.
At an early age, Elijah showed a mechanical interest, often taking items apart and putting them back together again. Recognizing his keen abilities, George and Emillia saved enough money to send Elijah to Edinburgh, Scotland, where he could study mechanical engineering. After finishing his studies as a “master mechanic and engineer” he returned to the United States which had just seen the end of the Civil War and the emergence of the “Emancipation Proclamation.”
Elijah moved to Ypsilanti, Michigan but was unable to find work as an engineer due to racial barriers. He was thus forced to take on a position as a fireman and oilman on the Michigan Central Railroad. As a fireman, McCoy was responsible for shoveling coal onto fires which would help to produce steam that powered the locomotive. As an oilman, Elijah was responsible for ensuring that the train was well lubricated. After a few miles, the train would be forced to stop, and he would have to walk alongside the train applying oil to the axles and bearings.
In an effort to improve efficiency and eliminate the frequent stopping necessary for lubrication of the train, McCoy set out to create a method of automating the task. In 1872 he developed a “lubricating cup” that could automatically drip oil when and where needed. He received a patent for the device later that year. The “lubricating cup” met with enormous success, and orders for it came in from railroad companies all over the country. Other inventors attempted to sell their own versions of the device, but most companies wanted the authentic device, requesting “The Real McCoy.”
Dr. Aprille Ericsson was born in Brooklyn, New York in 1963 and raised in the Bedford Stuyvesant neighborhood of Brooklyn. In junior high she won second place in the science fair, played on the girls’ basketball team and was a member of the science club, honors club and school band.
Although Aprille passed all entrance exams for New York’s technical high schools, she chose to move to Cambridge, Massachusetts to live with her grandparents and attend the Cambridge School of Weston. In high school she participated in both citywide and intramural softball and basketball leagues, while earning high scholastic honors. She was also accepted into the rigorous academic enrichment program, UNITE (now known as the Minority Introduction to Engineering, Entrepreneurship and Science or MITE.)
Dr. Aprille Ericcson graduated high school with top honors and attended the Massachusetts Institute of Technology (MIT) where she was involved in several research projects with the applied Physics Laboratory that included the development of a fiber optic laser gyroscope, and the creation of a database for EVA neutral buoyancy data calculated at the NASA Johnson Space Center.
After earning a Bachelor of Science degree in Aeronautical/ Astronautical Engineering at MIT, Dr. Ericcson attended Howard University in Washington, D.C. She became the first African- American woman to receive a Ph.D. in mechanical engineering at Howard University and the first female African-American to receive a doctorate in engineering from the NASA Goddard Space Flight Center.
Discussing her internship at the NASA Goddard Space Flight Center during school, Dr. Ericcson explained how she was offered a full-time position there after obtaining her Ph.D., “That’s how I did it. Once you get your foot in the door and meet people, you can show them that you are capable of doing the type of work that’s done here.”
Her many honors include: The Women’s Network, Top 18 Women Who Will Change the World; Women in Science and Engineering for Engineering Achievement; National Technical Association, Top 50 Minority Women in Science and Engineering, 1996-97; NASA representative to the White House; and most recently in 2016, the Prestigious Washington Award.
More about JEM Engineering
JEM Engineering’s team boasts over 150 years of combined experience, allowing it to take an antenna concept all the way through to full-scale production. Not only do we deliver quickly, we also extend our full satisfaction guarantee to all of our customers on all of our products, as well as our services. We are a 100% women owned small business.
JEM Engineering boasts two antenna testing chambers at our facility in Laurel, MD, within easy reach of both Baltimore and Washington DC.
Customers testing at JEM have the advantage of working with our knowledgeable and experienced RF technicians and engineers, who provide guidance and support to the testing experience, as well as assist with data analysis and interpretation. While our experts can easily determine which chamber is suitable for a particular test, it’s also helpful to know what each chamber’s capabilities are.
The TATF is ideal for testing over a variety of frequencies.
A Tapered Antenna Test Facility (TATF) Chamber provides powerful validation capabilities over a wide frequency range, allowing the testing of antennas and antenna systems for a variety of applications. Using these tools, we can measure radiation patterns, antenna gain (peak, average, max linear, min linear, H and V) and axial ratio from 80 MHz to 40 GHz.
Measurement accuracy is critical, and the TATF chamber offers accuracy of peak gain measurements ± 1.0 dB from 80 to 400 MHz, ± 0.7 dB from 400 MHz to 1 GHz, and ± 0.5 dB from 1 GHz to 18 GHz. The data analysis and reduction software supports a wide range of outputs, including radiation patterns and swept gain. Our engineers can also produce ASCII data files compatible with third party analysis tools such as MATLAB®, MathCAD® or EXCEL®
Test times depend on the number of frequency points taken, the number of angular steps measured, and the amount of noise correction applied. The max power at the input port of the PNA is +30 dBm; however, we can add a pad in line to allow gain much higher (as much as +110 dBm).
The SNF can test a smaller range of frequencies, but it can complete tests in as little as 15 minutes.
A Spherical Near-Field (SNF) antenna test chamber is the fastest facility available for full 4 pi steradian data collection. It uses an array of electronically scanned probes to scan a full 360-degree measurement plane, giving technicians the ability to complete measurements in minutes rather than hours.
This chamber can perform tests over frequencies from 400 MHz to 6 GHz, enabling testing of antennas for AMP, PCS, GSM, Bluetooth™, IEEE 802.11, GPS and other new and evolving wireless systems.
The spherical chamber at the testing facility at JEM can be customized to work for any antenna. While existing structures are in place that work with testing for most antennae, JEM Engineering also works with customers to custom design fixtures that will work to test any type of device.
The SNF Test Chamber can be used to test active devices, antennae with an amplifier or an attenuator, and even can be used to test a body worn or handheld device on a subject. By mounting the antennas in free space or on human subjects allows for the measurement of radiation patterns, efficiency, average gain, and any human body interaction to the radiating device. As with the TATF, our engineers can produce test information in a variety of formats.
*25dBi is the ceiling for gain measurements. A pad can be installed in our system to protect the equipment from saturation.
Request A Quote for Testing Services in the TATF or SNF at JEM Engineering
Learn firsthand how JEM Engineering is dedicated to developing and producing top quality antennas for their customers. Contact JEM Engineering for a free consultation and a quote on testing your antenna in the TATF and SNF Chambers at JEM.
Did you know that National STEM Day falls on the 8th of November each year? That’s because the abbreviation “NOV8” actually stands for “INNOVATE.”
STEM is all about innovation. The goal of STEM Day is to not only acknowledge those who work in fields related to Science, Technology, Engineering, and Mathematics, but also to encourage young minds to follow their passions and pursue such careers.
JEM Engineering is proud to have an extremely skilled and diverse group of individuals who make things happen! We asked our very own Matt Berry (Mechanical Engineer) and Anjali Bhattarai (Electrical Engineer) to talk about why they chose their career paths.
What is it about engineering that interests you?
M: Problem-solving. Also, the most satisfying thing about engineering is thought that the 3D models and design documents you spent time developing on your computer will eventually be held in your hand – your hard work has become a real thing. (Read more about the process of developing a product here.)
A: As an electrical engineer, I find the concept of energy very enticing. Every object in the universe requires energy to perform its activity. Having the opportunity to generate and control electrical energy is definitely the best part. There’s also the added benefit of working with high tech gizmos like cell phones and smartwatches before they hit the market.
Did you always know that you wanted to be an engineer? If not, what was your first career choice and what made you switch to engineering?
M: In high school, my success in STEM subjects led me to take an Architectural AutoCAD class at the Career and Technology Center in Frederick, MD. Thinking that I wanted to study architecture, I also participated in the ACE Mentor Program, which focused on orienting students with the fields of architecture, construction, and engineering. I realized later that architecture was not the correct fit since it was more art-rather than math- and science-based. Not knowing exactly what I wanted to do, I then transitioned to pursuing my degree in mechanical engineering, since it’s widely applicable to many fields (ie. aerospace engineering, civil engineering, etc.)
A: As a kid, I wanted to be an archaeologist. I later acknowledged my knack for analytical thinking, so I pursued engineering during my high school years, and later received a full scholarship to study engineering in college.
What would you say to persuade or encourage someone to study –or even pursue a career– in STEM?
M: STEM explains how things work, from something as simple as how water freezes to as complicated as a how a space shuttle can reach the moon. Engineering is problem solving and design. Both can be applied to any career you may see yourself doing, whether it be handling the foot traffic of hikers or directing water away from trails at a national park, or designing a robotic prosthetic to help those with a missing limb. Engineering is fun and challenging every day.
A: It pays well (laughs). As an engineer, you earn the skill set to transform your imagination into reality. Engineering teaches you how to better your concept and design through trial and error. It also alters your way of thinking by sharpening your analytical skills, making it easier to grasp any concept quicker. You become a problem solver and tackle important issues of the world. For instance, I once helped design a robot that could isolate and burn off cancer cells without harming healthy organs. With further research, it could have replaced chemotherapy.
Like Matt and Anjali, JEM Engineering proudly supports students and professionals in pursuit of careers in STEM!
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.
An unmanned aerial vehicle, or UAV, refer to a vehicle that is able to fly remotely, either with some sort of controller or autonomously. An unmanned aircraft system, or UAS, includes not only the UAV, itself but also the person on the ground controlling the flight, as well as the system in place that connects the two of them.
UAVs vary in weight and size, ranging from vehicles measurable by a few inches to aircraft with wingspans of up to 400 feet. Among numerous other factors, UAVs also vary in altitude and general operating characteristics. While there is no widely used classification system for UAVs, there are six major classifications for their functionality: target and decoy, reconnaissance, combat, logistics, research and development (R&D), civil, and commercial. Target and decoy UAVs are typically used for military training purposes. Reconnaissance and combat UAVs are used in the battlefield for intelligence attack capability in high-risk missions. As the name suggests, logistics UAVs are used for cargo and logistics operations. Likewise, R&D UAVs are used to further develop UAV technologies.
A Steadily Growing Industry
The UAV Manufacturing industry is in the growth stage of its life cycle. The defense sector currently is, and will likely continue to be, the primary market for UAVs. While most systems will be used for fighter combat, stealth missions, aircraft carrier operations, surveillance, and military communications, industry trends suggest that there will also be a steady expansion in the civil, as well as commercial uses for UAVs. Manufacturers are becoming increasingly focused on developing aircraft for the uses of border enforcement, humanitarian relief, search and rescue, scientific research, meteorology, firefighting, precision agriculture, infrastructure surveying, police surveillance, freight delivery and communication signals relaying.
Although the industry is heavily regulated, more business have been able to operate commercial drones since 2016, following the Federal Aviation Administration’s (FAA) issuance of new and less restrictive regulations. Researches, such as those at IBIS World, suggest that the finalization of FAA regulations over the next few years will create more demand for UAV industry products.
The manufacturing of UAVs requires a significant amount of electronic components for data recording and transmission purposes, as well as for avionic functions. Antennas are among the most important electronic components of any UAV or UAS, for they allow the vehicle to transmit information to and receive information from other systems, as well as the people on the ground.
Over the past 15 years, JEM Engineering has developed a variety of UAV-qualified antennas. We offer a selection of aerodynamic antennas in various form factors and frequency ranges. Our versatile antennas can be used in ground‐to-ground, ground‐to‐air, and air‐to‐ground communications systems. Our product applications include signal intelligence (SIGINT); intelligence, surveillance, and reconnaissance (ISR); and sensor systems.
To learn more about our UAV antennas, feel free to contact one of our experts.
RF testing is used to measure a variety of different antenna attributes.
In this post, we discus a few ways in which rf testing can help determine if your device is performing the way it should.
Measuring Radiation Patterns – An antenna’s radiation pattern measures the strength of its radio waves in relation to the direction at which the waves travel. 3-Dimensional and/or 2-Dimensional renderings of the radiation pattern make it possible to visualize which direction(s) the antenna is radiating the strongest, as well as where it loses strength. Finding this pattern is fundamental in determining the antenna’s functionality.
Measuring Antenna Efficiency – The radiation efficiency, or simply “efficiency” of an antenna is commonly defined as the ratio of the power radiated from the antenna, in relation to the power delivered to the antenna. This measurement is typically measured in decibels (dB). It is important to determine that an antenna is performing at a certain level of efficiency before it used for its intended purpose. Significant discrepancies in efficiency may be the result of a manufacturing defect or design flaw.
Measuring Antenna Gain – An antenna’s gain is a measurement that combines the antenna’s efficiency with its directivity, which is essentially the antenna’s ability to receive energy better from a particular direction. It is beneficial to have higher gain when there is a predetermined direction that the antenna will be receiving a signal from. In contrast, lower gains are preferable when receiving signals from multiple unspecified directions. Therefore, measuring gain is important in qualifying an antenna, particularly for its direction-finding and/or signal-receiving abilities.
Realizing any Effects on the Human Body – It is important to make sure that the use of certain antennas, especially those that are to be worn on one’s person, will not have adverse effects on the human body. Some testing chambers, such as the SNF chamber at JEM Engineering’s facility in Laurel, are able to accommodate human test subjects.
At JEM, we understand that accurate measurement of antenna electrical performance is critical. Therefore we offer a range of rapid antenna testing services from 80 MHz to 40 GHz. Our TATF and SNF test chambers are able to deliver the aforementioned measurements within hours, as opposed to days. Our experts also specialize in analyzing the data, helping our clients improve and perfect their custom product designs. For more information, feel free to contact us.
We are experts in custom antenna design and manufacturing for various applications. Some common applications include vehicular, airborne, communications, SIGINT (signal intelligence), and ISR (intelligence, surveillance, and reconnaissance). While certain antenna types are more suitable for each of these specific applications, many of our products are versatile and multi-platform.
In this article, we take a look at some of the different antenna types, and what applications they can be used for.
Broadband Antennas – These antennas operate over a wide band of frequencies, or “bandwidths.” Generally, the bandwidths over which they operate are higher than 1 octave. They come in a variety of forms, including spirals, log-periodic antennas, dipoles and Vivaldi notch elements.
An example of a broadband antenna, the HSA-056 is a 6″ spiral ideally suited for handheld and vehicular applications. With its wide bandwidth, broad beamwidth, and high RF efficiency, the antenna is also suitable for applications such as SIGINT, EW, and wideband communications.
Narrowband Antenna – In contrast to broadband antennas, narrowband antennas operate over relatively narrow bandwidths, generally much less than 1 octave. Patch and resonant cavity antennas are typical examples of narrowband antennas.
The RDF-8696 is a narrowband transducer for short range reading and writing of RFID tags including GEN2 tags. Some of the applications it can be used for include printers and various forms of automation equipment.
Antenna Arrays & Beamformers – Array antennas consist of multiple radiating elements. In some cases, these elements are fed by a corporate power divider or “beamformer.” The simplest beamformer is a power division network, which yields a fixed radiation beam. A beamformer that incorporates controllable phase or delay elements is called a steerable beam array or “phased array.”
Also nicknamed the “Hexband Array,” the MBA-0127 is compact, low-profile, single-port antenna covering multiple bands from 400MHz to 2.2GHz. This array is useful for multiband communications, airborne applications, ISR applications, and SIGINT.
Genetic Antenna – These antennas are designed entirely by an optimization algorithm, which can be a genetic algorithm or some other iterative method. While many antennas are pre-existent designs that are modified through optimizations, these antennas are entirely new designs generated solely via computer.
Genetic antennas are perhaps the most unique, mainly because they are almost completely custom, like the one pictured above.
“STEM” stands for Science, Technology, Engineering, and Mathematics.
In celebration of STEM Day (November 8) we asked our CEO, Nancy Lilly, and our Director of Antenna Development, Victor Sanchez, why they decided to pursue a career in STEM, and this is what they said...
JEM Engineering proudly supports students and professionals in pursuit of careers in STEM, for our company is built on the passions of such individuals.
More About Nancy
Nancy Lilly has significant RF experience working in a variety of engineering capacities. Before launching JEM Engineering in 2001, Nancy was a manufacturing engineer for both Wang and Scope Laboratories of Northern VA. She has more than 10 years of experience in antenna and RF applications and system design. She also has experience in quality engineering. Previously, she was quality assurance manager for Racal Avionics of Silver Spring, MD and a quality engineer for Arbitron of Columbia, MD. Nancy was an examiner for the 2004 U.S. Senate Productivity & Maryland Quality Awards for The University of Maryland Center for Quality & Productivity. Nancy holds a BS in both chemistry and industrial engineering from the University of Puerto Rico and Polytechnic University, respectively. She also holds a master’s degree in Engineering Administration from George Washington University.
As Chief Executive Officer and President of JEM, Nancy has received numerous awards, including the National Association of Professional and Executive Women’s “Woman of the Year Award” for her contributions to antenna design and manufacturing. In 2006, Nancy was selected among Maryland’s “Top 100 Minority Business Enterprise Awardees.”
More About Victor
Victor Sanchez has over 25 years of experience working in the field of RF / Antenna Engineering. He has a proven record of successful antenna development, technical innovation and program management. His roles have ranged from Research & Development to Integration & Test for breadboard and production antennas ranging from single elements at UHF to Ka-band phased arrays. He has conducted this work in both small and large team environments at Atlantic Aerospace Electronics Corporation, L-3 Communications and Northrop Grumman Corporation. While at Northrop Grumman, he earned an “Innovation of the Year Award” for his Broadband Additively Manufactured Array Antenna. He is currently Director of Antenna Engineering at JEM Engineering, where his principal responsibilities involve acquisition and technical execution of both government funded R&D and commercial antenna projects.
Victor holds BSEE and MSEE degrees in Electrical Engineering from the University of Massachusetts. He is a senior member of the Institute of Electrical Electronic Engineers (IEEE) and has numerous technical publications and patents, including the Monolithic Phased Array Antenna System.
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.