What material is commonly used for the radome of missiles like the AIM-120?

The use of polymer composite materials for the radomes of missiles such as the AIM-120 is primarily due to their excellent balance of properties. These materials are lightweight, which is crucial for maintaining the missile's overall performance and maneuverability.

Polymer composites also provide excellent electromagnetic transparency, which allows radar signals to pass through with minimal attenuation. This characteristic is essential for the missile's guidance systems to function effectively, as they rely on radar for target acquisition and tracking.

In addition to their performance benefits, polymer composites also offer high resistance to environmental factors, such as temperature changes and moisture, which ensures the durability and reliability of the radome in various operational conditions. The choice of polymer composites over metals like aluminum alloy or materials like borosilicate glass highlights their suitability for advanced missile technology where performance, weight, and durability are critical.