Microwave Absorbers for Anechoic Chambers
Microwave Absorbers for Anechoic Chambers
High-performance microwave absorber foam for RF testing environments. Our carbon-loaded polyurethane pyramidal absorbers provide effective electromagnetic absorption across microwave frequencies from 300 MHz to 110 GHz. NRL 8000 certified for fire safety. In stock and ships from California in 1-2 days.
What is a Microwave Absorber?
A microwave absorber is a specialized RF absorber optimized for absorbing electromagnetic energy in the microwave frequency range (300 MHz to 300 GHz). Our pyramidal absorbers are engineered with carbon-loaded polyurethane foam that converts electromagnetic waves into heat through dielectric and magnetic loss mechanisms.
All of our RF absorber products function as microwave absorbers - they're the same thing. "Microwave" simply refers to the frequency range where these absorbers excel at minimizing reflections and controlling electromagnetic interference.
Microwave Absorber Products
Our pyramidal foam absorbers provide broadband microwave absorption for anechoic chambers, EMC testing facilities, and communication system labs. Shop all sizes
2-Inch Pyramidal Absorber
- Effective frequency: 1.5 GHz and above
- Perfect for: 5G/6G device testing, WiFi 6E, Bluetooth, IoT devices
- Class A fire rated (ASTM E84)
4-Inch Pyramidal Absorber
- Effective frequency: 1 GHz and above
- Perfect for: Satellite communications, radar components, C-band testing
- Extended low-frequency performance
8-Inch Pyramidal Absorber
- Effective frequency: 500 MHz and above
- Perfect for: Cellular infrastructure, UHF/microwave hybrid testing
- Bridges UHF and microwave bands
12-Inch Pyramidal Absorber
- Effective frequency: 300 MHz and above
- Perfect for: Military radar, satellite ground stations, broadcast equipment
- Maximum low-frequency absorption
All absorbers maintain high performance up to 110 GHz, covering the entire microwave spectrum including millimeter-wave frequencies.
Microwave Absorber Applications
5G and 6G Wireless Testing
Test smartphones, base stations, and mmWave antennas in controlled environments. Our 2-inch and 4-inch absorbers are ideal for sub-6 GHz and mmWave frequency bands (24-47 GHz).
Satellite Communication Equipment
Verify performance of satellite modems, ground station equipment, and Ka-band (26-40 GHz) components with our broadband microwave absorbers.
Radar System Development
Test automotive radar (77-81 GHz), weather radar, and defense radar systems in anechoic chambers lined with our pyramidal absorbers.
Microwave Oven EMC Testing
Ensure consumer and industrial microwave ovens meet FCC and international EMC requirements by eliminating reflections in your test chamber.
IoT Device Certification
Certify Zigbee, Thread, Matter, and other IoT protocols operating in 2.4 GHz and 5 GHz ISM bands.
Materials That Absorb Microwaves: Carbon-Loaded Polyurethane Foam
Our microwave absorbing material uses volumetrically loaded carbon particles suspended throughout open-cell polyurethane foam. This construction provides several advantages:
Broadband Absorption: The pyramidal geometry and carbon loading create effective absorption across decades of bandwidth - from VHF through millimeter-wave frequencies.
Structural Stability: Unlike ferrite tiles or hybrid absorbers, polyurethane foam is lightweight, easy to install, and won't crumble or degrade over time.
Fire Safety Certified: Independently tested to ASTM E84-25a Class A standards, meeting building codes for commercial installations.
Cost-Effective: Carbon-loaded foam provides excellent performance at a fraction of the cost of ferrite or hybrid absorber solutions.
Why Choose dB Absorber for Microwave Testing?
NRL 8000 Certified
Our foam meets U.S. Navy specifications NRL 8000 I, II, and III for flammability - the most stringent fire safety standards for RF absorbers. This certification is required for government and defense installations.
In Stock, Fast Shipping
Unlike competitors with 6-8 week lead times, we stock all standard sizes and ship from California within 1-2 business days. Get your chamber operational faster.
Proven Performance to 110 GHz
Tested and verified performance across the full microwave spectrum, including emerging 5G mmWave and 6G experimental bands up to 110 GHz.
Made for Professional Testing Labs
Electronics manufacturers, government agencies, universities, and commercial EMC testing labs trust dB Absorber for mission-critical RF testing environments.
Get Started
Ready to outfit your anechoic chamber with high-performance microwave absorbers?
Shop Microwave Absorbers | View Test Results
Questions? Contact our RF engineering team at sales@dbabsorber.com
Related Resources
Learn more about microwave absorbers and RF testing:
- Microwave Absorbers for Communication Testing: Why They're Essential
- How Effective Are Pyramidal Absorbers in Minimizing Microwave Reflection?
- Microwave Absorbing Materials: From Foams to Films
- How Microwave Absorbers Work: Dielectric & Magnetic Loss Mechanisms
- What is Anechoic?
- NRL 8000 Fire Safety Requirements
Microwave Absorber FAQs
What frequencies do microwave absorbers cover?
Our pyramidal microwave absorbers provide effective absorption from 300 MHz to 110 GHz, depending on absorber height. The 2-inch model covers 3 GHz and above, ideal for most microwave applications. For sub-GHz microwave testing, choose 8-inch (500 MHz+) or 12-inch (300 MHz+) absorbers. All sizes maintain excellent performance through millimeter-wave frequencies up to 110 GHz.
Can your absorbers be used for 5G and millimeter-wave testing?
Yes. Our absorbers are verified to 110 GHz, covering all current and planned 5G NR bands including FR1 (sub-6 GHz) and FR2 (24–52 GHz) as well as experimental 6G bands up to W-band. The 2-inch and 4-inch sizes are most commonly used for 5G device testing chambers.
What is the difference between a microwave absorber and an RF absorber?
They are the same product. "Microwave absorber" and "RF absorber" both refer to materials that absorb electromagnetic energy. "Microwave" typically emphasizes the frequency range (roughly 300 MHz to 300 GHz), while "RF absorber" is the broader term. Our pyramidal absorbers function across both RF and microwave frequencies.
How are microwave absorbers installed in a chamber?
Pyramidal absorbers are bonded to chamber walls and ceiling using contact adhesive or specialized RF-transparent adhesive. The absorber tiles (24″ × 24″ base) are placed tip-out with the pyramidal points facing the interior of the chamber. Proper installation ensures no gaps between tiles. For installation guidance, contact our team at sales@dbabsorber.com.
How long do microwave absorbers last?
Carbon-loaded polyurethane foam absorbers typically last 15–25 years in a properly maintained indoor environment. Performance degrades gradually if the foam is exposed to excessive moisture, UV light, or physical damage. Our absorbers are tested for dimensional stability under varying temperature and humidity conditions.
Related: Explore our RF absorber products or read more on our technology blog.
