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 -10 dB bandwidth is from 2.1 to 15.4 GHz (only a little higher than -10 dB around 7.5 GHz). The radiation patterns retain symmetry and are relatively stable at 2.5, 8 and 11 GHz. The monostatic RCS performance in four different incident cases is studied to obtain some helpful conclusions for the RCS reduction of the UWB antenna. The RCS achieves effective reduction in comparison with that of the reference antenna. The largest reduction is 4.1, 19.8, 3.9dBsm in three different incident cases, respectively, while the largest loss of gain is only about -1.3 dB. The antenna suits the occasion of desiring UWB antenna with low RCS.