A HOLLY-LEAF-SHAPED MONOPOLE ANTENNA WITH LOW RCS FOR UWB APPLICATION

As to low observable platform, one of the major contributing sources of target RCS is the scattering due to onboard antennas. So the research on RCS reduction of the antenna is important. In this paper, a holly-leaf-shaped monopole antenna with low RCS is designed. A square notch is etched to improve impedance matching and expand the bandwidth in the ground. The measured i10dB bandwidth is from 2.1 to 15.4GHz (only a little higher than i10dB around 7.5GHz). The radiation patterns retain symmetry and are relatively stable at 2.5, 8 and 11GHz. The monostatic RCS performance in four difierent incident cases is studied to obtain some helpful conclusions for the RCS reduction of the UWB antenna. The RCS achieves efiective reduction in comparison with that of the reference antenna. The largest reduction is 4.1, 19.8, 3.9dBsm in three difierent incident cases, respectively, while the largest loss of gain is only about i1:3dB. The antenna suits the occasion of desiring UWB antenna with low RCS.