SWRA705 August   2021 AWR1243 , AWR1443 , AWR1642 , AWR1843 , AWR1843AOP , AWR2243 , AWR2944 , AWR6443 , AWR6843 , AWR6843AOP , AWRL1432 , AWRL6432 , IWR1443 , IWR1642 , IWR1843 , IWR2243 , IWR6243 , IWR6443 , IWR6843 , IWR6843AOP , IWRL6432 , IWRL6432AOP

 

  1.   Trademarks
  2. 1 Introduction and Challenges
  3. 2 Radome Design Elements
    1. 2.1 Understanding Dielectric Constant and Loss tangent on Radome and Antenna Design
    2. 2.2 Impedance Mismatch at Radome Boundaries
    3. 2.3 Radome Wall Thickness
    4. 2.4 Antenna to Radome Distance
  4. 3 Typical Radome Material Examples
  5. 4 Radome Angle Dependent Error
    1. 4.1 Rectangular Radome Angle Dependent Error
    2. 4.2 Spherical Radome Angle Dependent Error
    3. 4.3 Effect of the Angle Error in the Application
  6. 5 Radome Design and Simulations
  7. 6 Radome Lab Experiments
    1. 6.1 Radome Experiment – 1: Flat Plastic Radome
    2. 6.2 PTFE Material Rectangular Radome
    3. 6.3 PTFE-Based Curved Radome
  8. 7 Additional Considerations
    1. 7.1 Antenna Calibration
    2. 7.2 Radome Near Proximity Considerations
  9. 8 Summary
  10. 9 Acknowledgments
  11. 10References

3 Typical Radome Material Examples

Materials with lower Dk (dielectric constant) and Df (loss tangent) are recommended for radome designs. Typical materials used in radomes are PBT (Polybutylene terephthalate), Plexiglas, Polycarbonate, Teflon® (PTFE), Polystyrene, and ABS. It is important to avoid metal fixings and coatings (especially metallic paint that will reduce the signal strength significantly), see [10].

In addition, the material used should be homogeneous in nature, in order to not create any additional Dk boundaries within the radome itself, with the design aiming for the walls to be solid with no air bubbles or other material fragments inside. There are radome designs that incorporate a sandwich structure with different materials, mainly for strength and possible bandwidth improvements, but those types are not covered in this document.

Table 3-1 Permittivity and Dissipation Factor for Different Radome Materials
Materials Permittivity (εr) Dissipation Factor (tanδ)
Polycarbonate 2.9 0.012
ABS 2.0-3.5 0.0050-0.019
PEEK 3.2 0.0048
PTFE (Teflon®) 2 <0.0002
Plexiglass® 2.6 0.009
Glass 5.75 0.003
Ceramics 9.8 0.0005
PE 2.3 0.0003
PBT 2.9-4.0 0.002