To imitate the broken situation of the conductive threads of the wearable antenna, a strip-ground design of rectangular patch antenna with the conventional substrate is presented to investigate the change of the antenna performance, where the ground is sliced along its E-plane. The strips are symmetrical along the center line of the width of the patch, and the gap ratio of the gap to the solid ground varies with the change of gaps. The conventional patch antenna is used as a reference for comparison with the stripe-ground antennas. And the effect of the coaxial cable, the changes of the impedance, and the cross-polarization of the antenna are investigated. Several antenna prototypes are fabricated and their measured results are in good agreement with the simulations. These results show that the gaps change the performance of the strip-ground antennas, but they can work well if the gap ratio is less than 1 : 4.

A sidelobe-suppression technique for the reflector antenna is proposed. Compared to the conventional reflector antenna analysis technique, the proposed technique adopts the novel quasi-actual feed instead of the traditional imaginary feed to calculate and optimize the radiation pattern of the reflector antenna. The calculated and the optimized radiation results obtained by the proposed technique are more accurate since the quasi-actual feed data is closer to that of the practical feed. In the proposed technique, the sidelobes are suppressed by optimizing the shape of the reflector illuminated by the quasi-actual feed. The reflector shape is smoothly transformed by the non-uniform rational B-spline technique and the scatter of the reflector is efficiently calculated by the physical optics and the Gauss-Legendre quadrature algorithms. The pattern result of this proposed technique is compared with the result simulated by FEKO software, a good agreement is achieved and has a higher efficiency. As an example of applying the proposed technique, an unshaped and a shaped reflector antennas with the same feed and the same size are designed, fabricated and tested, and the measured results agree well with the expectations on the low sidelobe characteristic.

The aim of this study is to efficiently excite the radiation of phase gradient metasurface (PGM), a novel coplanar discontinuous transmission line feed is proposed for reduction of the profile, where 12 uniform discontinuous rectangular rings form the feeding structure. The unit cells of PGM are symmetrically placed on both sides of this feed structure at the same layer, and they are close enough. The measurements agree well with those of simulations in the range of 10.48–11.18 GHz.