Broadband dual‐polarised antenna with wideband decoupling structure for polarisation diversity wireless communication application

Abstract

A broadband dual‐polarised antenna with wideband decoupling structure is presented. By using the improved dipole, the proposed antenna achieves a common impedance bandwidth of 62% ranging from 1.645 to 3.13 GHz with standing a wave ratio <1.5. For improving the port isolations of the prototype, wideband isolation enhance technique is proposed. By using this technique, an average port isolation enhancement of 6 dB is realised within a wider bandwidth than 1 GHz. The bandwidth extension and decoupling mechanism are discussed. Moreover, the radiation patterns, gain and total radiation efficiency of the proposed antenna are also studied and presented. Experimental results demonstrate that the antenna has many advantages such as high gain (8.5 ± 0.7dBi), good radiation efficiency (>90.9%) and high cross polarisation discrimination. It is very suitable for polarisation diversity wireless communication application.

A Wideband Dual-Polarized Antenna and its Array With Electrically Downtilt Function for 5G Sub-6 GHz Communication Applications

“…When low and high resonant modes are combined together, a wide impedance bandwidth is achieved. The antennas described in [1]- [7] adopt this principle, but they only use two inherent resonant modes of dipole, making it impossible to achieve enough operating bandwidth (covering LTE and 5G sub-6 GHz) to meet the needs for global future communication. The proposed antenna uses three resonant modes to extend the bandwidth.…”

“…In terms of the antenna element design, cross dipoles are the most popular way to realize dual-polarization and high port-to-port isolation. Dipoles can be designed with different shape and size [1]- [7], such as fan-shaped dipoles [1], loop dipoles [2]- [5], and diamond-shaped dipoles [6], [7]. The The associate editor coordinating the review of this manuscript and approving it for publication was Mengmeng Li.…”

“…After adding the cells, the second mode moves towards low frequency and combines with the first mode to achieve a wide bandwidth from about 1.7 to 2.8 GHz. In addition, some researchers adopt coupling feeding structures [4], [5] and balun-feeding structure [6], [7] to get a similar frequency coverage. To increase antenna bandwidth further, the dipoles in [4]- [7] add additional resonant structures like independent loops [4] embedded loops [5], closed slots [6] and vertically parasitic patch [7] to create additional third resonant mode at high frequency.…”

“…In addition, some researchers adopt coupling feeding structures [4], [5] and balun-feeding structure [6], [7] to get a similar frequency coverage. To increase antenna bandwidth further, the dipoles in [4]- [7] add additional resonant structures like independent loops [4] embedded loops [5], closed slots [6] and vertically parasitic patch [7] to create additional third resonant mode at high frequency. However, due to the narrow bandwidth of the third resonant mode, the above dipoles can only cover the maximum bandwidth from 1.64 to 3.13 GHz, which is not enough to meet the requirements of next 5G communication, especially for the critical 5G sub-6 GHz band N78 from 3.3 to 3.8 GHz.…”