A wideband dual-polarised patch antenna with high isolation and a low cross-polarisation level is presented. Two orthogonal linearly-polarised modes are excited by the electromagnetic-fed structure. One of the two modes is excited by a pair of hook-shaped probes with a 180 o phase difference; while the other is excited by a magnetic-coupled loop, which is comprised of a metal loop and an open-ended transmission line. By introducing two shorting pins, the isolation between two feeding ports can be enhanced to more than 40 dB. Moreover, the radiation patterns in the ± 45°planes have a cross-polarisation level of less than − 30 dB within the 3 dB beam widths. The measured − 10 dB reflection coefficients bandwidth of the two modes are 40.7% (2.45-3.7 GHz) and 38.7% (2.6-3.85 GHz). The gains of the proposed antenna are about 8.7 and 9.1 dBi over the operating band. Thus, this antenna is highly suitable for the base station antenna that is required to cover the operating bandwidth of 3.5 GHz WiMAX systems.

Polarization three-dimensional (3D) imaging technology has received extensive attention in recent years because of its advantages of high accuracy, long detection distance, simplicity, and low cost. The ambiguity in the normal obtained by the polarization characteristics of the target’s specular or diffuse reflected light limits the development of polarization 3D imaging technology. Over the past few decades, many shape from polarization techniques have been proposed to address the ambiguity issues, i.e., high-precision normal acquisition. Meanwhile, some polarization 3D imaging techniques attempt to extend experimental objects to complex specific targets and scenarios through a learning-based approach. Additionally, other problems and related solutions in polarization 3D imaging technology are also investigated. In this paper, the fundamental principles behind these technologies will be elucidated, experimental results will be presented to demonstrate the capabilities and limitations of these popular technologies, and finally, our perspectives on the remaining challenges of the polarization 3D imaging technology will be presented.