News | March 26, 2020

Recent Developments With High Power RF Absorber

In recent years, there has been an increased need for testing active RF antenna arrays and radar systems at high power. Since absorber works by transforming electromagnetic energy into thermal energy, there is a danger that in the presence of high fields, the absorber will reach temperatures that will cause it to ignite. When companies make a considerable financial investment with an absorber lined test chamber, they are also committed to protecting their equipment and the safety of their personnel. To address these concerns, ETS-Lindgren's engineers have devoted their expertise to the research and development of high power absorber to gain a greater understanding of this complex material. As a result, ETS-Lindgren offers a wide range of high power absorber for RF and Microwave applications.

"We started our research by collecting temperature data for our polyurethane absorber under varying field strengths at 12.4 GHz, both on the surface and inside the absorber to get a thorough understanding of the entire piece of absorber," said Zhong Chen, Director of RF Engineering with ETS-Lindgren. "Several effects impact the absorber's internal temperature for the same incident field level at the front of the absorber, such as the antenna test distance to the absorber, the shape of the absorber pyramid, and the measurement frequency. Our research provided greater insight into the heat dissipation and temperature distribution inside the absorber. After validating our simulation models, we have great confidence in the performance and power handling capability of our absorber."

Among the key findings of the R&D, our team learned that absorber with a slender profile provides improved power handling capabilities and that applying forced air at a relatively low flow rate can significantly decrease the absorber temperature. More information on this research may be found in the following papers presented at the Antenna Measurement Techniques Association (AMTA) symposiums: "Multiphysics Analysis of RF Pyramidal Absorbers" and "Surface and Internal Temperature versus Incident Field Measurements of Polyurethane Based Absorbers in the Ku Band."

With over 10,000 enclosure installations globally, ETS-Lindgren is a leader in the design and installation of anechoic chambers for EMC and RF test applications, including per the military and commercial standards MIL-STD-461, ANSI C63.4, CISPR 16 and CISPR 25. The absorber is manufactured at ETS-Lindgren's facility in the United States and available for installations worldwide. To ensure high quality, each piece of absorber is tested and serialized prior to shipment. To assist you with selecting the best absorber for your application, read the Top 10 Absorber Considerations for RF and Microwave Applications. View our complete line of absorber, including for EMC applications, here at

About ETS-Lindgren
ETS-Lindgren is an international manufacturer of components and systems that measure, shield, and control electromagnetic and acoustic energy. The company's products are used for electromagnetic compatibility (EMC), microwave and wireless testing, electromagnetic field (EMF) measurement, radio frequency (RF) personal safety monitoring, magnetic resonance imaging (MRI), and control of acoustic environments.

Headquartered in Cedar Park, Texas, ETS-Lindgren has manufacturing facilities in North America, Europe and Asia. The company is a wholly owned subsidiary of ESCO Technologies, a leading supplier of engineered products for growing industrial and commercial markets. ESCO is a New York Stock Exchange listed company (symbol ESE) with headquarters in St. Louis, Missouri. For more information, visit

Source: ETS-Lindgren