Figure 1: A radome kept stable with atmospheric overpressure for a precision approach radar.
Figure 2: the radome top of the mountain “Großer Arber” (Germany)
Figure 3: Radome made of fibre-glass reinforced polymer resin with an air conditioning system for an ATC-radar
A radome is a structural, weatherproof enclosure used to protect an antenna. The material used in building the radome allows a relatively unattenuated electromagnetic signal between the antenna inside the radome and outside equipment. Radomes are used to protect the surfaces of the antenna from the effects of environmental exposure.
Radomes can be constructed in several shapes depending upon the particular application using various construction materials (fiberglass, PTFE-coated fabric, etc.). When used on UAVs or other aircraft, in addition to such protection, the radome also streamlines the antenna system, thus reducing drag.
The word radome is a portmanteau of radar and dome.
This protective shell should reflect, absorb, refract or scatter the electromagnetic radiation as little as possible and should have the lowest possible transmission attenuation. The attenuation of a radome for radar units acts equally on the transmitting path and on the receiving path. This is why it is referred to as “two-way attenuation.” A typical value for two-way attenuation for a radome made of foamed material is 0.3 dB, which is a total loss of about 7 % of the high-frequency energy. According to the radar equation this is about 2 % range loss.