Introduction
Exposure to harsh environmental conditions such as heavy rain, extreme temperatures, and strong winds can have adverse effects on the way the antenna transmits or receives signals. To protect antennas from these conditions and other environmental factors, enclosures known as radomes can be placed around them. An efficient radome shall be transparent to electromagnetic signals while meeting the physical and aerodynamic requirements. It is crucial that the radome be rigid and averts the accumulation of ice and water. The operating frequency, the material and the shape of the radome can influence the antenna radiation and lead to bigger losses.
HFWorks Modeling of Antenna Radomes
To contribute to this research effort, we used our virtual prototyping electromagnetic software, HFWorks, to design two different antenna radomes that have minimum effects on the antenna performance.
Spherical Radome
Spherical Radome
Animation of Different Scanning Angles
The above antenna radome is simulated, and the following results are obtained.
Electric Field Animation (10.5 GHz)
Return Loss
2D Radiation Pattern (10.5 GHz)
3D Radiation Pattern ( 10.5 GHz)
Antenna Far-Field Parameters (10.5 GHz)
2D Radiation Pattern (5o, 10.5 GHz)
2D Radiation Pattern (10o, 10.5 GHz)
From the above figures, we can observe that the antenna boresight remains intact. The radome introduces a slight increase in the sidelobe levels and a minimal decrease in the antenna gain for different scanning angles.
Nose Cone Radome
The optimal distance between the antenna and the radome minimizes the reflection effects caused by the radome. The effects will become minimal when the reflected waves are in-phase with the transmitted waves.
Nose Cone Radome
Animation of Spacing Between the Radome and the Antenna
Electric Field Animation (Vector Plot, 10.5 GHz)
Return Loss
3D Radiation Pattern (d=170 mm and f= 10.5 GHz)
2D Radiation Pattern (10.5 GHz)
Using parameterization, we can notice that placing the radome 155 mm away from the antenna causes the least distortion for the antenna radiation as compared with other scenarios.
A radome is a crucial weatherproof enclosure that protects the antenna from the environment. Placing the antenna under a radome has been a challenging endeavor for antenna engineers as there are many design parameters to consider. The use of A-sandwich radome can improve the overall antenna performance by introducing no boresight error, a minimal gain reduction, and a small increase of sidelobe levels. HFWorks has been efficient in overcoming antenna challenges and improving the antenna radome performance.