A Dual-Band Dual-Polarized Stacked Microstrip Antenna With High-Isolation and Band-Notch Characteristics for 5G Microcell Communications

A dual-band dual-polarized stacked microstrip antenna with high-isolation and band-notch characteristics is proposed. The proposed antenna is comprised of three layers of substrate. To obtain high isolation between two input ports, a pair of orthogonal differentially driven feeding lines are printed on the top side of the bottom layer. To yield the desired lower-and upper-frequency bandwidths for 5G microcell communications, two sets of 2x2 radiating patch arrays are printed on the second and top layer substrates, respectively. Compared with the conventional microstrip antenna, besides demonstrating a smaller size of 0.48 x 0.48 x 0.085 lambda(3)(0), the proposed antenna has also exhibited higher isolation of better than 40 dB and higher gain of >8 dBi. Finally, a novel technique of arranging four meander lines that connects the four array elements printed on the second layer substrate is proposed to achieve an adjustable band-notch characteristic.