Overview
The C-RAM RFA is a similar convoluted absorber available in various thickness grades. It is made from a large-pore open-cell urethane foam (approx 15 pores/inch). This open cell structure makes C-RAM RFA ideal for outdoor applications, where rain can drain quickly through the piece, and residual moisture can evaporate quickly.
For optimum resistance to moisture, C-RAM RFA uses a different fire retardancy mechanism. While it is self-extinguishing, this material is not rated to NRL 8093 standards.
METHOD OF APPLICATION
C-RAMRFA are attached to walls and ceilings using a contact adhesive, such as CAMBOND 934. When bonding over a vent or air duct, the absorber should be cut oversized, and be bonded only around the edges to the wall.
AVAILABILITY
C-RAM RFC and RFA are each available in three thickness grades, as specified in the tables below. Pieces are available in a standard 24 in x 24 in (610 x 610 mm) base size, although other dimensions can be made on special order.
Both materials are generally supplied with a light blue surface coating, but as with C-RAM FAC, when the intended use is above 30 GHz, it is recommended to specify the material unpainted.
| TYPICAL DIMENSIONS AND REFLECTIVITIES OF C-RAM RFA | |||||||||
| GRADE | HEIGHT in. (mm) | WEIGHT Lbs. (kg) | Reflectivity at Frequency in dB | ||||||
| 2 GHz | 5 GHz | 10 GHz | 15 GHz | 20 GHz | |||||
| RFA-075 | 0.75 in 19mm | 0.5 lb .25kg | -5 | -25 | -35 | -45 | |||
| RFA-175 | 1.75 in 45mm | 0.8 lb .35kg | -5 | -10 | -30 | -45 | -50 | ||
| RFA-375 | 3.75 in 95mm | 1.5 lb .70kg | 25 | 32 | -37 | -40 | -40 | ||
