A Compact, Ultrawideband Dual-Polarized Vivaldi Antenna With Radar Cross Section Reduction
Ke Zhang, R.-S. Tan, Zhi Hao Jiang, Yong Huang, Lin Tang, Wei Hong
Abstract
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 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> λ<sub>L</sub></i> × 0.5 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> λ<sub>L</sub></i> , where <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">λ<sub>L</sub></i> is the free-space wavelength at the lowest working frequency. The antenna is fabricated and characterized, showing a measured <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S<sub>ii</sub></i> < −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 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i> - and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</i> -polarized plane waves, respectively. The demonstrated antenna is useful in a wide variety of applications such as the near-field measurement systems.