The radome will naturally provide an exterior surface where other environmental layers will form, and can subsequently affect the performance of the system. This topic is not discussed in this document, however, some of these example challenges are listed below:

• Wet grass/mud deposits for lawn mowers
• Dust and mud deposits for off road vehicles
• Metallic dust, and other dusts deposits for factory vehicles
• Water absorption of the radome can be an important artifact since the electrical properties will change.
• Ice and snow formation on the radome for cars and outside vehicles or on the exterior of surveillance radar sensors can significantly reduces the dynamic range of the radar detection capability. This is typically handled by embedding a heater into the radome when the radar is deployed in areas where it can be directly exposed to precipitation.

To address some of the above challenges requires either manual or built-in cleaning systems, which can be triggered by the radar system after detecting that RF visibility has been obscured using custom built-in diagnostics.

In the case of an enclosure with metal as part of structure, which can also serve as a heatsink, the metal parts should not protrude into the field of view of antenna.

In some cases, within the radome, to prevent multiple reflections from the radome walls to PCB, it is good practice to use absorber material wherever it’s feasible. Other techniques, such as the traditional use of PCB potting for environmental protection, should be avoided when it comes to covering the antenna elements. These materials tend to have a variable thickness with unknown Dk characteristics and can severely degrade the performance of the antenna. However, a very thin (~1 μm) low loss coating material [11] can be used over the antenna structures for if additional protection is required.