Your choice of absorber material may require special formulations and physical geometries to meet your unique requirements. Here are some of the top tips from the experts at ETS Lindgren to aid in your selection process:
Know how anechoic absorber works.
Absorber is designed to reduce reflections from impinging electromagnetic (EM) waves, and “absorb” incident EM energy.
Match absorber design to application.
Absorber works by dissipating the EM energy inside the absorber and turning it into heat. In most RF, microwave and antenna applications, the lossy dielectric works best because of superior EM absorption at higher frequencies.
Pyramidal shape influences absorber performance.
Broadband absorbers work by avoiding “sudden” changes in impedance for the impinging wave and gradually terminate and absorb the EM wave.
Specify absorber for RF performance.
Absorber is specified for reflectivity as a function of frequency at normal incident angle. Understand that reflectivity degrades at larger incident angles.
Match absorber length and shape for your application.
Pyramidal absorber length determines how well it can work at the lowest frequencies.
Use commonly available absorber lengths.
Save money, speed delivery by choosing absorber in typical, off the shelf lengths.
Determine maximum power handling capability of absorber.
Polyurethane absorbers are specified to withstand a maximum power of W/in2 of continuous wave (CW) incident field under room temperature with no additional forced airflow.
Manufacturing process impacts absorber quality.
Find a computer controlled manufacturing process that begins with homogeneous blocks of polyurethane foam.
Use non-hygroscopic absorber.
Maintain a stable absorber electrical property and RF reflectivity by reducing moisture, which affects electrical conductivity significantly.
Confirm RF performance verification testing.
Ask how your supplier tests the absorber to verify performance reflectivity before shipment. Is each piece of absorber tested or sample tested one piece per batch? Is each piece serialized? Ask these questions protect your investment!
This is a sponsored post published in the September 2019 issue of The Product Insights newsletter. If you would like to receive tips like this and more, directly to your inbox each month, please subscribe.