A Compact, Ultrawideband Dual-Polarized Vivaldi Antenna With Radar Cross Section Reduction

A compact, ultrawideband (UWB) dual-polarized Vivaldi antenna with radar cross section (RCS) reduction is proposed and demonstrated. The dual-polarized antenna is constructed by aligning two single-polarized Vivaldi elements into a crossshaped arrangement. By cutting symmetric rectangular inclined slots and curved metal potions out from the radiating surfaces, the RCS of the antenna can be suppressed over a broad frequency band. The antenna possesses a footprint of 0.58
λ_L
× 0.5
λ_L
, where
λ_L
is the free-space wavelength at the lowest working frequency. The antenna is fabricated and characterized, showing a measured
S_ii
< −10 dB covering the UWB band ranging from 1.8 to 6 GHz. Moreover, the measured port isolation is higher than 23 dB, whereas the averaged monostatic RCS is smaller than −30.2 and −28 dBsm under the illumination of
x
- and
y
-polarized plane waves, respectively. The demonstrated antenna is useful in a wide variety of applications such as the near-field measurement systems.