A Low-profile Dual-band Dual-polarization Co-aperture Array Antenna with High Isolation

This paper proposes a low-profile high-isolation dual-polarization array antenna operating in the L/S band. The radiating unit of the array antenna adopts U-shaped bending dipoles to realize the staggered arrangement of high- and low-band units, and is connected to the feeding network by a coaxial cable. To achieve the non-influence of high-band and low-band feed networks, multi-layer printing technology is used and grooves are etched on the metal plate. In order to reduce the coupling of the high- and low-band dipoles at low frequency, a bandpass filter is added to the high-band feed network, which greatly improves the isolation at low-frequency. The measured results show that the impedance bandwidth of the array is 4.5% (0.971-1.015 GHz) and 7.5% (1.89-2.04 GHz), with gains of 15 and 19 dBi at 1 GHz and 2 GHz, respectively. And the isolation between the dual-polarized ports more than 50 dB and 35 dB was achieved at 1 GHz and 2 GHz, respectively. The proposed array will have practical value in L/S band full-duplex wireless communication systems.