Antenna Engineering Blog

JEM Partners with the American Red Cross to support disaster relief

JEM Engineering, through the American Red Cross, will be providing financial assistance to households that were severely impacted by recent Hurricanes Harvey and Irma, as well as the impending Hurricane Jose.

As part of our efforts, we are also collecting monetary donations from the community. If you are interested in donating, you may contact us for additional information.

Why donate through JEM? Make your donations go twice as far!

Every gift you make is significant in our disaster relief efforts. We want to double your gifts so that our efforts will move twice as fast! JEM will match donations you make by 100%.

Are your antennas up to the test?

JEM Engineering's SNF Chamber in Laurel, MD

Like with most products, an antenna’s outstanding performance in the field must be preceded by outstanding performance in the lab.

It is JEM Engineering’s job to not only design and manufacture antenna products, but also to qualify them to meet RF specifications, as well as environmental standards such as military standard MIL-STD-810 and RTCA/DO-160. Because of this, not only do our products survive strenuous environmental conditions; they perform well. We extend the same guarantee to our customers by offering them the same qualification services.

Our rigorous qualification procedures combine our own internal testing capabilities with those of our external testing partners. In this post, we list some of our in-house qualification capabilities.

• Efficiency Measurements

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. JEM’s Spherical Near-field Chamber (SNF) and Tapered Antenna Test Facility (TATF) chambers generate efficiency plots, in addition to as addition to radiation patterns, and ASCII Data Files.

• Directivity Measurements

Directivity is one on of an antenna’s key performance factors. One can define it as the ability of an antenna to focus energy in a particular direction when transmitting. Directivity also measures the antenna’s ability to receive energy better from a particular direction.

• Gain Measurements

Another useful performance measurement is the antenna’s gain. It combines the antenna’s efficiency with its directivity. The gain measurements we provide as part of our data package include peak, average, maximum linear, minimum linear, horizontal, and vertical, as applicable. Additionally, SNF and TATF chambers generate gain measurements for antennas within two different frequency ranges. The SNF measures from 400 MHz to 6 GHz , while the TATF measures 80 MHz to 40 GHz.

• VSWR and Return Loss

Voltage standing wave ratio, or “VSWR,” is a measure that describes how well the antenna impedance -or voltage to the current at the antenna’s input- “matches” to the radio or transmission line it is connected to. A good match allows a transmitter or receiver to deliver power to an antenna without excessive reflection back on the line (return loss). At JEM, a single VSWR measurment, including system calibration, takes less than 10 minutes. In fact, minus calibration, it only takes 1 minute or less to complete a test!

• Radiation Patterns

An antenna’s radiation pattern measures the strength of its radio waves in relation to the direction at which the waves travel. We can generate both 3-Dimensional, as well as 2-Dimensional renderings of radiation patterns.


Steered Array 3-D Pot	Steered Array 2-D Plot

• Human Body Interaction

Besides producing full-spherical radiation patterns, our SNF chamber can accommodate a human test subject. This allows us to take accurate measurements of body interaction effects on body worn and handheld devices.

JEM Engineering technicians testing a wearable antenna in our SNF chamber in Laurel, MD

• Temperature Effects

Temperature testing allows us to determine how a complete product, its parts, and its sub-assemblies are affected by extreme temperatures, as well as changes in temperatures. Consequently, this also allows us to assist customers in analyzing the cost effectiveness of manufacturing a product and using its components.

• Simulations

Our team of experts has access to advanced simulation software, therefore, allowing us to measure in-situ performance, and eliminating need to run a physical test.

Our Communications Antennas

At JEM we offer a variety of communications antennas, each tailored to meet a specific need. In this article, we reintroduce some of our comms antennas.

Handheld Communications Antennas – Our high-power antennas are ground plane independent. The ruggedized, weather-resistant JEM‐9051 is just one of the handheld communication antennas we designed. Nicknamed “The Power Ducky”, it is a flexible whip antenna covering 90 – 512 MHz with 25 W CW of power handling. This antenna is designed for low‐profile and man‐portable wideband communications using high power amplifiers.

Communications Antennas: JEM-9051

+ High Power Handheld Antenna

+ Ground Plane Independent

+ Class Leading Gain & Pattern

QHA-081| Frequency Band: 800-1000 MHz | VSWR: <2.0:1 | Polarization: Circular, RHCP | Gain: >8dBi | Power: 25 Watts CWIn-building Communications Antennas – One of our antenna products’ common features is versatility. The QHA-081 right-hand Helix Antenna is circularly polarized, operating at frequencies 800-1000 MHz. Aside from in-building communications, this antenna is suitable for multiple wireless applications.

+ Circularly Polarized

+ Designed for in-building communications

+ Suitable for Multiple Wireless Applications

Unmanned Aerial Vehicle (UAV) Communications Antennas – Another versatile antenna is the UVW-1547, a UAV and vehicular qualified antenna is designed for ground-to-ground, ground-to-air, and air-to-ground communications systems. This antenna is optimized for the L, S, and C-band downlinks with low drag operations. The antenna is also optimal for SIGINT and sensor systems.

Communications Antennas: UVW-1547

+ Designed for Ground‐to-Ground,Ground‐to‐Air, and Air‐to‐Ground Communications Systems

+ Suitable for SIGINT, ISR, and Sensor Systems

+ Optional magnetic mount or tubular chassis mounting assembly

Satellite (SATCOM) Communications Antennas – We have developed a number of antennas used for satellite communications, many of which can also be mounted onto a vehicle’s or an aircraft’s surface with no degradation to the pattern or VSWR. The HSA‐2438LP, also known as the “Low-Profule MUOS SATCOM Antenna” is a hybrid spiral antenna operates on 240 – 380 MHz. It can be flush mounted on a vehicle or airborne surface and its pattern is designed for uniform gain overhead to 40 degrees in elevation.

Communications Antennas: HSA-2438LP

+ Flush mountable for low visibility

+ Ground Plane Independent

+ Optional Clamp Mounts for Quick Connect in All-Terrain Vehicle Operation

More about JEM Engineering

JEM Engineering’s team boasts over 150 years of combined experience, allowing them to take an antenna concept all the way through to full-scale production. All JEM’s antennas are qualified and tested in-house at their facility in Laurel, MD.

JEM Engineering Releases HSA-2438MFC

JEM Engineering is proud to announce the release of our newest product, the HSA-2438MFC.

This groundbreaking Low-Profile MFC (Magnetic Flux Channel) technology, combined with a JEM’s novel beamforming technology, provides AS‐3916 performance in SINCGARS band, exceptional UHF LOS gain, and UHF UFO/MUOS SATCOM capabilities in a 1” thick low‐profile form‐factor.

Additional Information

Contact JEM Engineering for more information. To download the spec sheet, or to view all of our vehicular products, visit our product page.

HSA-2438MFC

SNF Chamber Testing Capabilities

The SNF chamber testing facility at JEM Engineering provides fast results to government and commercial groups looking to collect 4 pi steradian data. The electronically scanned probes take in readings from a full 360 degree measurement plane and can perform tests over frequencies from 400 MHz to 6 GHz. The SNF test chamber can analyze radiation patterns, efficiency, average gain and human body interaction of wireless system antennas for AMP, PCS, GSM, Bluetooth, IEEE 802.11, GPS and others.

SNF Custom Test Chamber

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. We will even build a custom fixture for you, if needed. The JEM 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. Testing times will depend on the number of frequency points measured, but tests of even over 100 Frequency Points can be completed from measurement to data results in about 10 minutes.

Analyses For SNF Antenna Test

Results from the Spherical Near-Field Antenna Test can be presented in a variety of data formats, making them usable for future testing simulations. The data export is in ASCII text format which can be used in most standard software packages (such as Excel), and data can be exported according to customer requirements. This data can be modeled in 3D or 2D Radiation Patterns, Swept Gain and Efficiency plots, or used in simulations. Data packages typically consist of one or some of the following:

Full spherical E-Phi and E-Theta values at each frequency
Maximum Gain measured – Polarization, Phase and Amplitude
Efficiency in dB and %
Axial Ratio
Individual Phi and Theta cuts

JEM Engineering is prepared to handle sight sensitive and classified samples. The SNF testing range is in a building that can be isolated for classified samples, if requested.

JEM Engineering Quality Commitment Guarantee

JEM has decades of experience in the custom antenna design and development and RF testing services industry. We promise customers a full 100% satisfaction guarantee of products and services, including rapid testing services for government and commercial applications.

At JEM, we are dedicated to improving performance, efficiency and overall business of our customers. Because of this dedication, we are always innovating alongside our customers to improve current products and tackle challenges.

Request A Quote for Testing Services in the Spherical Near-Field Chamber 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 SNF Chamber at JEM.

Rapid Antenna Testing Services At JEM Engineering

At JEM Engineering, we understand that accurate measurement of antenna electrical performance is critical. That’s why we offer a range of rapid testing services from 50 MHz to 40 GHz for antenna, microwave and communication systems.

Rapid RF Testing Services

Complete tests in minutes instead of days
Frequency ranges from 50 MHz to 40 GHz, covering standards such as Bluetooth™, WiFi, WiMAX, GPS, cellular, and more!
Capabilities Including:
- Radiation patterns
- Antenna gain and efficiency
- Axial ratio
- Human body interaction effects
Multiple test chambers to fit your needs
Variety of data format options, patterns and plots, including:
- 2D and 3D Radiation patterns from our Spherical Near-Field (SNF) Chamber
- Swept gain and efficiency
- ASCII data
Data files can be processed using a variety of software, such as:
- MATLAB®
- MathCAD®
- EXCEL®
Data can be saved directly and securely to a customer’s own hard drive on-site

Our Location

JEM houses multiple RF test chambers at our facility in Laurel, MD, within easy reach of both Baltimore and Washington DC, and convenient to Dulles International, BWI, and Reagan Washington National airports.

Customers testing at JEM have the advantage of working with our knowledgeable and experienced onsite RF technicians and engineers, who provide guidance and support to the testing experience and can assist with data analysis and interpretation.

Our Promise

We have the highest commitment to your business’s proprietary designs and trade secrets, keeping everything you give us – as well as resulting test data – under careful lock and key. Furthermore, we promise to provide the most experienced test technicians and antenna engineers, providing you with the best value of high accuracy antenna testing in the industry.

Get A Rapid Antenna Testing Quote Now

To learn more and to find out if rapid RF testing from JEM Engineering is a good fit for you project, contact us at (301) 317-1070 or request a quote online for antenna testing services.

Custom Engineering Antenna Development

UHF Monocone Antenna For quick turnaround custom antenna engineering with 100% satisfaction guarantee, partner with JEM Engineering. We offer custom antenna products, development, and testing services using our in-house rapid prototyping and testing facilities from 2 MHz to 40 GHz, including a tapered far-field anechoic chamber and a high-speed spherical near to far-field anechoic chamber.

Antenna Engineering

With expertise in quick-reaction custom antenna development, novel antenna products, and rapid RF testing services for both government and commercial applications, the engineers at JEM have decades of combined experience in the development and validation of antennas, microwave circuits, phased arrays and associated electronics.

Custom Antenna Development

JEM Engineering’s extensive antenna development experience allows us to design, build and validate custom antennas for a variety of applications. Some of the types of antennas we specialize in include:

Broadband Antennas – These antennas operate over a wide band of frequencies such as spirals, log-periodic dipoles and Vivaldi notch elements.
Narrowband Antennas – These antennas operate over narrow bandwidths, including patch and resonant cavity antennas.
Genetic Antennas – These antennas are designed by a computer based on an optimization algorithm, such as a genetic algorithm or some other iterative method.
Array Antenna & Beamformers – An array antenna consists of multiple radiating elements sometimes fed by a corporate power divider or beamformer.
Housings, Assemblies, and Structural Components – These are the mechanical components created to support electrical designs, and can range from simple enclosures, to protective covers, to mounting hardware, to moving mechanical structures.

The JEM Difference

JEM’s commitment to quality is instilled throughout every area of the company, from front-desk operations to prototyping, and we continue to grow our network of quality and compliance professionals.

Our transparent quality policy is met by:

Meeting our customers’ requirements and expectations;
Continually improving our product, striving to ship defect-free products;
Continually improving the effectiveness of our quality management system; and
Maintaining a motivated and highly skilled team.

Contact JEM Engineering For A Quote On Custom Antenna Development Services

See how JEM Engineering can bring your custom antenna needs to life. Contact us for a complimentary consultation and quote on custom antenna engineering services.

Woman-owned antenna engineering firm offers TATF and TAC chamber testing for government and commercial use

about-us-snfring JEM Engineering, LLC houses multiple RF test chambers at its facility in Laurel, Maryland, within easy reach of both Baltimore and Washington, District of Columbia. JEM has two anechoic test chambers, a spherical near-field chamber and a tapered antenna test chamber, which are used for both government and commercial applications. Customers testing at JEM have the advantage of working with knowledgeable and experienced RF technicians and engineers, who provide guidance and support to the testing experience and can assist with data analysis and interpretation.

Data files are available in a variety of easy-to-handle formats, and can be processed using software such as MATLAB, MathCAD or EXCEL. JEM can also generate a variety of useful reports and plots, including 3D radiation patterns for data collected using its Spherical Near-Field (SNF) Chamber. 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. ASCII data files are easily processed by third party analysis tools such as MATLAB, MathCAD or EXCEL.

RF antenna testing is only one of the services that JEM Engineering offers. The company, founded in 2001, also specializes in quick-reaction custom antenna design and development, and novel antenna products. JEM’s product offering includes, but is not limited to, radome antennas, vehicle mounted antennas, flight qualified antennas, monitoring antennas, outdoor antennas, concealed antannas, portable antennas, magnetic antennas, web antennas, communication antennas. JEM Engineering proudly holds ISO 9001:2008 certification.