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Overview
The anechoic chamber or shielded enclosure is lined with absorbing material, which can absorb
electromagnetic  waves and reduce  or  eliminate the reflection  and  scattering  of  radio waves.  The
performance  of  the anechoic chamber is  closely related  to  the absorbing performance,  frequency
band characteristics, shape, thickness and type of the absorbing material.  The more electromagnetic
waves  absorbed  by  absorber,  the  smaller  the  reflection,  so  that  the surrounding environment is
getting closer to free space, and the performance of the anechoic chamber is better.
Absorbing materials include polyurethane foam,  polystyrene,  rubber and other materials.  Select the
size,  shape and material  of  the RF absorber according  to  the size and application  of  the  anechoic
chamber or shielded enclosure. It is also necessary to consider the absorbing performance, frequency
band, price and weight of the RF absorber.
 
High Performance Microwave Pyramidal Absorber
HR-HPM  Absorber is a series of high  performance  broadband RF  absorbers mad  efrom specially treated
low  density  polyurethane  foam.  The  product is  flexible  and  tolerant of  physical  abuse.  Using a  steep
pyramid design which provides an impedance gradient, HR-HPM Absorber provides premium performance
in  anechoic  chambers  at  both  normal  and  off-normal  incidence  angles.  These  products mee t of  the
flame-retardant  requirements of  UL-94-HBF  horizontal burning  foamed material test, ROHS compliant is
according to IEC 62321 and meet Halogen-Free test of EN14582.
 
Key Features
Typical weights, dimensions, and reflectivity  Of the various grades of HR-HPM Absorber are  given in
the tables on the below. 
 
Typically, HR-HPM Absorbers can handle up to 1.0  W/in2  (2 kW/m2)  of RF energy  in a temperature 
controlled room, but this is dependent upon frequency and application. 
The product is black thro ughout, and generally is sprayed with a light blue surface  coating, both for
cleanliness and to provide better light reflection inside a chamber.
The absorber can be left unpainted if requested.
       	
        
     
    
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AVAILABILITY
Standard sizes of HR-HPM are listed in Table 1, ranging from a 1 inch to 72 inch height.
In addition to simply supplying a bill of materials, HANRUIN designs and installs complete
anechoic chambers. Chambers can be designed to meet your specifications, and an entire
kit of materials is supplied, including factory pre-cuts of special fitting parts. We can install
all materials or supply technical support to help you complete your own installation.
HYSICAL CHARACTERISTICS AND TYPICAL REFLECTIVITY AT NORMAL INCIDENCE
   	
         
     
    
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