rf testing

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.

Remote Radio Frequency Testing

JEM Engineering offers all of our customers the added convenience of performing remote radio frequency testing

 

We find that most of our customers prefer to visit our facilities for their scheduled radio frequency tests. However, JEM also offers the option of remote testing, which may be preferable, depending on the specific requirements and circumstances.

 

The main purpose of our remote testing is to provide customers with the same quality rf tests without the need to travel (and the expenses associated with travel). Remote testing also comes at no extra cost. Our invoicing only takes into account our current rates and how much chamber time is spent on each test, no more, no less. 

 

The process of scheduling a remote test is as simple as scheduling an onsite test and involves no additional paperwork.

 

1. Call or email us to begin the quoting process. Whenever a customer inquires after our in-house or remote radio frequency testing services, we walk them through the same steps to determine how much chamber time is needed to complete the test. The customer fills out a form, which outlines the passive test requirements. Once we receive the form (which we commonly refer to as the “Test Plan”), we start generating the quote. Depending on the requirements, we can then determine whether or not the test is suitable for remote testing and most tests are. 

 

2. We schedule the test together. If a test date has not been specified prior to quoting, our team will consult with the customer to determine the best available date(s) to perform the test.

 

3. The customer ships the unit(s) and any additional equipment necessary to complete the test. The customer is responsible for any applicable fees associated with shipping and insurance.

 

4. Upon receipt of the components, we begin the test as scheduled. Throughout the testing process, our experts remain in communication with our customers to eliminate any confusion and ensure accurate results.

 

5. When the test is complete, we ship everything back, carefully packaged. We work with the recipient to send every component back via their preferred courier.

 

6. We invoice the customer. Our standard invoicing schedule is Net 10. Any deviation from this payment method will have been discussed prior to scheduling the test.

 

Our company takes pride in our flexibility when working with customers. 

We understand that sometimes an onsite test becomes a remote test. In the event that travel is either inconvenient or no longer feasible, our technicians will perform the test(s) as scheduled, provided that we have received all the necessary components. If there is any delay on the sender’s part, we will also hold customer property for a specified amount of time, as outlined by our Terms and Conditions.*

 

In summation, almost any and every test performed onsite can be done completely remotely. As long as we have all the applicable components in-house, our experts can perform tests on even the largest units and with the most complex pieces of equipment.

 

* First-time customers receive a copy of our Terms & Conditions.

An Introduction to RF Testing

RF Testing | Measuring Effects on a Human Body

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.