Radome

Radome

Radomes made of PDCPD composite glass fiber not only offer excellent wave transmission but also withstand harsh conditions such as extreme cold, UV rays, and pollution.
Radars are critical structural components used to protect radar antenna systems. They not only shield the radar system from external environmental influences but also ensure signal attenuation during electromagnetic wave penetration, ensuring accurate radar system operation. With the widespread application of radar technology in aerospace, military equipment, civil communications, autonomous driving, and weather monitoring, the performance requirements for radomes are becoming increasingly stringent.

- Basic Functions
The core function of a radome is to provide comprehensive physical protection for the radar antenna without affecting the transmission and reception of radar electromagnetic waves. Its main functions include:
Electromagnetic transparency
The radome must maintain high transmittance for electromagnetic waves in a specific frequency band, without causing excessive signal reflection, refraction, attenuation, or phase distortion, ensuring that the radar maintains high-precision detection capabilities at long distances and in complex environments.
Environmental protection
Radar systems often operate in complex, variable, and even harsh natural environments, such as high altitude, low temperatures, high humidity, heavy rain, sandstorms, and snowstorms. Radomes provide sealing, isolation, waterproofing, corrosion resistance, dust protection, and UV protection, extending the service life of the radar system.
Structural impact resistance
In high-speed aircraft, ships, or ground-based mobile equipment, radomes must withstand strong wind pressure, high-speed impact, vibration, and thermal expansion and contraction, requiring a certain level of structural strength, rigidity, and toughness.
Aerodynamic optimization
Radars, especially on aircraft, must possess a good aerodynamic shape to reduce flight drag, mitigate turbulence interference, and improve flight efficiency and stability. Stealth Performance Support (Military)
Some radomes feature radar wave absorption or scattering designs to reduce the aircraft's radar cross-section (RCS), enhance stealth, and meet the electronic countermeasures requirements of modern warfare.

- Structural Characteristics
Radomes may appear simple in structure, but they must actually address a variety of complex performance requirements. They typically possess the following structural features:
Thin-walled shell structure
Most radomes are thin-walled spherical, conical, streamlined, or cylindrical structures, ensuring excellent aerodynamic performance and symmetrical electromagnetic characteristics while reducing overall weight.
Multi-layer composite design
Some high-performance radomes utilize multi-layer composite structures, such as dielectric, damping, and conductive layers. The combination of different materials creates a specific electromagnetic response, improving wave transmittance and reducing radar reflection.
Modular and maintainable design
To facilitate maintenance and upgrades, radome structures typically support rapid disassembly and replacement, while ensuring tight sealing and reliable mechanical connections.
Structural stability and thermal compensation design

- Material Selection
Radome materials must achieve a high degree of balance in electromagnetic, mechanical, and environmental compatibility. The main material types are as follows:
Glass Fiber Reinforced Plastic (GFRP)
A common radome material, it offers excellent wave transmission, mechanical strength, and weather resistance. GFRP is suitable for most civilian and military applications, and is particularly stable in low- and medium-frequency bands.
Foam Sandwich Composites
Lightweight foams such as PVC or PET foam are often used as interlayers in multilayer structures. These sandwich structures offer a good stiffness-to-weight ratio and are suitable for large radomes, such as aviation radomes.
Ceramic-Based Materials
Specialized ceramic materials are used in some radomes for high-frequency, high-temperature, or high-energy electromagnetic environments. These materials offer stable dielectric properties but are difficult to process. These materials are often used in space exploration or missile guidance systems.
Engineering Plastics Such as Polydicyclopentadiene (PDCPD)
Emerging high-performance materials such as PDCPD offer excellent impact resistance, dimensional stability, and corrosion resistance, making them suitable for molding complex shapes and for long-term service in harsh environments. Stealth Coatings and Absorbent Materials
Some military radomes are covered with specialized absorbing materials or coatings to reduce electromagnetic reflection and enhance the platform's stealth capabilities. These materials must possess high thermal conductivity, high-temperature resistance, and strong adhesion.

- Manufacturing Process
The manufacturing process is a crucial factor influencing radome performance. Different materials and application scenarios require different molding technologies:
Hand lay-up and spray molding
Suitable for small-batch, complex-shaped GFRP radomes. They offer flexibility and adaptability, but are highly labor-intensive and require strict product consistency control.
Autoclave and prepreg molding
Used for high-precision composite radomes, suitable for applications such as aerospace that demand high performance consistency. They offer high density and excellent surface quality, but require significant equipment and cost investment.
Vacuum Infusion Molding (VARTM)
A relatively advanced composite molding method suitable for medium-volume production, it features a high degree of process automation and allows for effective control of resin distribution and thickness accuracy.
Reaction Injection Molding (RIM)
Particularly suitable for thermoset materials such as PDCPD, it offers advantages such as rapid prototyping, single-shot molding of complex structures, and high surface quality. It is suitable for the production of large-scale or multi-curved radomes.
3D Printing and Digital Manufacturing
Used for prototyping, small-batch trial production, or structural verification, it facilitates rapid design iteration and customized development, and is particularly suitable for verifying complex stealth structures.

- Performance Indicators
High-performance radomes must meet precise requirements across multiple metrics to ensure overall system efficiency:
Electromagnetic Transmittance
The dielectric constant and loss tangent of the radome material within the target frequency band (such as the X-band, S-band, and K-band) determine its wave transmission capability. A radome with low wave transmission loss achieves negligible signal attenuation.
Structural Strength and Impact Resistance
The radome must withstand wind loads, vibrations, hail impacts, and high-speed airflow during flight. Impact resistance is a key indicator for assessing its safety.
Weather and Environmental Resistance
Material performance must remain stable over time, preventing deformation and degradation in environments with severe temperature fluctuations, strong UV rays, high humidity, salt spray, or sandstorms.
Thermal Stability and Thermal Conductivity
Preventing malfunction or degradation of the radome due to elevated temperatures is crucial, especially in high-power military radar systems.