snf chamber

Radiofrequency Test Fixtures

RF Test Fixtures

JEM Engineering offers both on-site and remote RF testing services at our facility in Laurel, Maryland. Our Spherical Near-Field Chamber (SNF) and Tapered Antenna Testing Facility (TATF) can measure a number of antenna performance factors.

While many tests do not require the use of a test fixture, tests that involve a full 3-dimensional measurements in our TATF chamber will require some type of interfacing with our roll arm.

What materials are used for RF test fixtures?

Dielectric (non-conductive) materials, such as foam and wood, for example, are ideal for test fixturing. Such materials can support antennas and radomes without affecting their RF performance characteristics during a test.

RF Test Fixtures

Does JEM Engineering provide its own test fixtures?

We house a variety of simple test fixtures, which we use to test our own antennas, as well as our customers’. Our existing structures allow us to fixture multiple antennas during the allotted test time. 

Customers may also provide their own test fixture(s).

What about custom fixtures?If the weight of the antenna under test is off-center by more than 36”, or if the antenna requires a more specific configuration, a custom fixture may be necessary.

We have the in-house capability to build custom fixtures. While customers are encouraged to provide their own fixturing specifications (for example, with drawings and dimensions), we are generally able to  fabricate the appropriate fixtures based on a unit’s design and specific test requirements.

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 Chamber Testing

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.