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Vol . 8      No. 2    April  2000

Radomes

tfapr22.jpg (10465 bytes)The radomes are electromagnetic windows protecting the antennas from environmental conditions without affecting their electrical characteristics significantly. It is a multidisciplinary area encompassing disciplines like electrical, structural and material sciences. The design of radome is complex requiring expertise in all the above disciplines. Requirements also vary depending on platform on which they are mounted, such as airborne, ship borne, submarine borne and ground-based. Airborne radomes have to withstand severe aerodynamic loads, temperature gradients, rain erosion, hail impact and high altitudes. Ground-based radomes have to meet different requirements like dust, blast, high temperature, and shock, while ship borne radomes have to withstand salt corrosion and fungus growth. In submarine radomes, high hydraulic pressures of the order of 70 bars have to be withstood. Hence, the environmental requirement plays an important role in the design of radomes for various applications.

Appropriate design expertise has been established in this critical area by using tfapr23.jpg (18694 bytes)state-of-the-art materials like synthetic foam as core and E-glass with low-loss resin as skin over a large frequency range 0.5 to 40 GHz. Radomes are realised in sandwich configurations for achieving high strength and broad-band width. Multi layer broad-band 'A' sandwich and two-ply radomes have been developed for low flying helicopters and supersonic fighter aircraft, respectively. Ultra-high strength 'C' sandwich radomes and high strength thin wall 'A' sandwich radomes have been developed for submarine platform and ground-based platforms, respectively. All these radomes have been subjected to rigorous electrical and environmental qualification tests. Production lines have been established for meeting the bulk requirements.